165161000 has 32 divisors (see below), whose sum is σ = 386479080. Its totient is φ = 66064000.

The previous prime is 165160991. The next prime is 165161021. The reversal of 165161000 is 161561.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 16467364 + 148693636 = 4058^2 + 12194^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 81581 + ... + 83580.

Almost surely, 2^165161000 is an apocalyptic number.

165161000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165161000 is an abundant number, since it is smaller than the sum of its proper divisors (221318080).

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

165161000 is a wasteful number, since it uses less digits than its factorization.

165161000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165182 (or 165168 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 165161000 is about 12851.4979671632. The cubic root of 165161000 is about 548.6589919695.

The spelling of 165161000 in words is "one hundred sixty-five million, one hundred sixty-one thousand".