153

153 = 3² x 17.

153 is the 17th triangular number. It is also a hexagonal number.

153 = 1! + 2! + 3! + 4! + 5!

153 is palindromic in base 2 (binary): 10011001. It is 2121 in base 4 and 99 in base 16.

153 is the smallest number greater than 1 such that the sum of the cubes of its digits equals itself: 153 = 1³ + 5³ + 3³.

153 has a representation as a sum of two squares: 153 = 3² + 12².

In the Bible, Simon Peter is said to have caught 153 fish (John 21:11).

Source: Number Gossip

378

378 = 2 x 3³ x 7.

378 is the 27th triangular number. It is also a hexagonal number and the smallest Smith triangular number.

378 is the smallest three-digit number in which the sum of the digits is equal to the sum of the prime factors: 3 + 7 + 8 = 2 + 3 + 3 + 3 + 7 = 18.

378 is a cake number.

378 Holmia is an asteroid discovered in 1893.

Source: Number Gossip

861

861 = 3 x 7 x 41.

861 is the 41st triangular number. It is also a hexagonal number.

861 = 7 + 77 + 777.

144,648 = 861 x 168 = 492 x 294.

The USS Harwood (DD 861) was a destroyer in the U.S. Navy just after World War II.

Source: What's Special About This Number?

703

703 = 19 x 37.

703 is the 37th triangular number. It is also a hexagonal number.

703 is a number that cannot be written as a sum of three squares.

703 is 3131 in base 6.

703 is the smallest number requiring 73 fifth powers for its Waring representation.

703 is one of the telephone area codes for northern Virginia.

Source: Wikipedia

325

325 = 5² x 13.

325 is the 25th triangular number (the sum of the first 25 integers): 1 + 2 + 3 + . . . + 25 = 325.

325 is a hexagonal number.

In base 2, 325 is the palindromic number 101000101; in base 4, it is 11011; and in base 8, it is 505.

325 is the smallest number to be the sum of two squares in three different ways: 325 = 1² + 18² = 6² + 17² = 10² + 15².

325 is the hypotenuse of two primitive Pythagorean triples: 325² = 36² + 323² = 204² + 253².

Currently undergoing restoration, the USS LST-325, launched in 1942, participated in the invasion of Sicily in 1943 and in June 1944 landed at Omaha Beach.

Source: Positive Integers

26

26 = 2 x 13.

26 is the only integer sandwiched between a square (25) and a cube (27).

26 is the smallest non-palindromic number whose square is palindromic: 26² = 676.

26 is equal to the sum of the digits of its cube: 26³ = 17,576 and 1 + 7 + 5 + 7 + 6 = 26.

26 (together with 11) cannot be represented as the sum of less than six hexagonal numbers from the sequence 1 6 15 28 45 . . . .

26 has a representation as a sum of two squares: 26 = 5² + 1².

26 is the smallest number with three representations as a sum of three distinct primes: 26 = 2 + 5 + 19 = 2 + 7 + 17 = 2 + 11 + 13.


26 is the atomic number of iron and the number of letters in the English alphabet.

Source: Number Gossip

435

435 = 3 x 5 x 29.

435 is a triangular number and a hexagonal number.

435 is the number of ordered partitions of 16 into distinct parts.

435 is the sum of seven positive fifth powers: 435 = 2⁵ + 2⁵ + 2⁵ + 2⁵ + 2⁵ + 2⁵ + 3⁵.

The United States House of Representatives has 435 members.

Source: The On-Line Encyclopedia of Integer Sequences