165866560 has 56 divisors (see below), whose sum is σ = 405673560. Its totient is φ = 64548864.

The previous prime is 165866557. The next prime is 165866587. The reversal of 165866560 is 65668561.

It can be written as a sum of positive squares in 4 ways, for example, as 69355584 + 96510976 = 8328^2 + 9824^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4836 + ... + 18844.

Almost surely, 2^165866560 is an apocalyptic number.

165866560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165866560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (202836780).

165866560 is an abundant number, since it is smaller than the sum of its proper divisors (239807000).

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

165866560 is a wasteful number, since it uses less digits than its factorization.

165866560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14063 (or 14053 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 43.

The square root of 165866560 is about 12878.9192093126. The cubic root of 165866560 is about 549.4391638458.

The spelling of 165866560 in words is "one hundred sixty-five million, eight hundred sixty-six thousand, five hundred sixty".