165904 has 10 divisors (see below), whose sum is σ = 321470. Its totient is φ = 82944.

The previous prime is 165901. The next prime is 165931. The reversal of 165904 is 409561.

It can be written as a sum of positive squares in only one way, i.e., 102400 + 63504 = 320^2 + 252^2 .

It is not an unprimeable number, because it can be changed into a prime (165901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5169 + ... + 5200.

It is an arithmetic number, because the mean of its divisors is an integer number (32147).

2¹⁶⁵⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

165904 is a deficient number, since it is larger than the sum of its proper divisors (155566).

165904 is a wasteful number, since it uses less digits than its factorization.

165904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10377 (or 10371 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 165904 is about 407.3131473449. The cubic root of 165904 is about 54.9480501201.

The spelling of 165904 in words is "one hundred sixty-five thousand, nine hundred four".