141

141 = 3 x 47.

141 is the first of eight consecutive numbers that each has precisely two principal divisors.

141 = 3 x 47
142 = 2 x 71
143 = 11 x 13
144 = 2⁴ x 3²
145 = 5 x 29
146 = 2 x 73
147 = 7 x 7²
148 = 2² x 37

141 is the first numerical palindrome that appears in the decimal expansion of pi: 3.14159 . . .

Cullen numbers have the form n2ⁿ + 1. They are prime for n = 1, 141, 4713, 5795, 6611, and 18496, and composite for every other n less than or equal to 30,000.

The Lockheed C-141 Starlifter was a U.S. military aircraft.

Source: Roger B. Eggleton and James A. MacDougall. 2008. Consecutive integers with equally many principal divisors. Mathematics Magazine 81(October):235-248.