165720880 has 40 divisors (see below), whose sum is σ = 414942192. Its totient is φ = 61188864.

The previous prime is 165720853. The next prime is 165720881. The reversal of 165720880 is 88027561.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (165720881) 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, 78634 + ... + 80713.

Almost surely, 2^165720880 is an apocalyptic number.

165720880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165720880 is an abundant number, since it is smaller than the sum of its proper divisors (249221312).

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

165720880 is a wasteful number, since it uses less digits than its factorization.

165720880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159373 (or 159367 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 165720880 is about 12873.2622128193. The cubic root of 165720880 is about 549.2782599190.

The spelling of 165720880 in words is "one hundred sixty-five million, seven hundred twenty thousand, eight hundred eighty".