165517980 has 24 divisors (see below), whose sum is σ = 463450512. Its totient is φ = 44138112.

The previous prime is 165517907. The next prime is 165517981. The reversal of 165517980 is 89715561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165517981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1379257 + ... + 1379376.

It is an arithmetic number, because the mean of its divisors is an integer number (19310438).

Almost surely, 2^165517980 is an apocalyptic number.

165517980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165517980 is an abundant number, since it is smaller than the sum of its proper divisors (297932532).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165517980 is a wasteful number, since it uses less digits than its factorization.

165517980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2758645 (or 2758643 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 42.

The square root of 165517980 is about 12865.3791238346. The cubic root of 165517980 is about 549.0539991543.

It can be divided in two parts, 16551 and 7980, that added together give a triangular number (24531 = T₂₂₁).

The spelling of 165517980 in words is "one hundred sixty-five million, five hundred seventeen thousand, nine hundred eighty".