165868641 has 33 divisors (see below), whose sum is σ = 253584499. Its totient is φ = 108492696.

The previous prime is 165868627. The next prime is 165868691. The reversal of 165868641 is 146868561.

The square root of 165868641 is 12879.

It is a perfect power (a square), and thus also a powerful number.

165868641 is a `hidden beast` number, since 1 + 6 + 586 + 8 + 64 + 1 = 666.

165868641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 119574225 + 46294416 = 10935^2 + 6804^2 .

It is not a de Polignac number, because 165868641 - 2²⁵ = 132314209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165868601) by changing a digit.

It is a polite number, since it can be written in 32 ways as a sum of consecutive naturals, for example, 3129571 + ... + 3129623.

Almost surely, 2^165868641 is an apocalyptic number.

165868641 is the 12879-th square number.

165868641 is the 6440-th centered octagonal number.

It is an amenable number.

165868641 is a deficient number, since it is larger than the sum of its proper divisors (87715858).

165868641 is an frugal number, since it uses more digits than its factorization.

165868641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 56 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The cubic root of 165868641 is about 549.4414616329.

The spelling of 165868641 in words is "one hundred sixty-five million, eight hundred sixty-eight thousand, six hundred forty-one".