1771

1771 = 7 x 11 x 23.

1771 is the smallest of three consecutive numbers that are products of exactly three primes (A113789).

1771 is the 21st tetrahedral number (A000292).

1771 is the concatenation of the 7th prime (17) and its reverse (71) (A067087).

1771 is a divisor of 45⁶ - 1.

1771 is a number n such that n² (3136441) is a concatenation of two nonzero squares (A048375): 3136 = 56² and 441 = 21².

Source: Number Gossip