20995904 has 14 divisors (see below), whose sum is σ = 41663874. Its totient is φ = 10497920.

The previous prime is 20995903. The next prime is 20995939. The reversal of 20995904 is 40959902.

It can be written as a sum of positive squares in only one way, i.e., 20430400 + 565504 = 4520^2 + 752^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20995903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163967 + ... + 164094.

It is an arithmetic number, because the mean of its divisors is an integer number (2975991).

Almost surely, 2^20995904 is an apocalyptic number.

It is an amenable number.

20995904 is a deficient number, since it is larger than the sum of its proper divisors (20667970).

20995904 is an equidigital number, since it uses as much as digits as its factorization.

20995904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328073 (or 328063 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 20995904 is about 4582.1287629223. The cubic root of 20995904 is about 275.8744790854.

The spelling of 20995904 in words is "twenty million, nine hundred ninety-five thousand, nine hundred four".