165865880 has 32 divisors (see below), whose sum is σ = 389426400. Its totient is φ = 63461376.

The previous prime is 165865879. The next prime is 165865883. The reversal of 165865880 is 88568561.

165865880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×165865880² = 55022980296348800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165865883) 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, 89225 + ... + 91064.

It is an arithmetic number, because the mean of its divisors is an integer number (12169575).

Almost surely, 2^165865880 is an apocalyptic number.

165865880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165865880 is an abundant number, since it is smaller than the sum of its proper divisors (223560520).

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

165865880 is a wasteful number, since it uses less digits than its factorization.

165865880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180323 (or 180319 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 47.

The square root of 165865880 is about 12878.8928095547. The cubic root of 165865880 is about 549.4384130030.

The spelling of 165865880 in words is "one hundred sixty-five million, eight hundred sixty-five thousand, eight hundred eighty".