20812864 has 14 divisors (see below), whose sum is σ = 41300654. Its totient is φ = 10406400.

The previous prime is 20812849. The next prime is 20812877. The reversal of 20812864 is 46821802.

It can be written as a sum of positive squares in only one way, i.e., 17572864 + 3240000 = 4192^2 + 1800^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 162537 + ... + 162664.

Almost surely, 2^20812864 is an apocalyptic number.

It is an amenable number.

20812864 is a deficient number, since it is larger than the sum of its proper divisors (20487790).

20812864 is an equidigital number, since it uses as much as digits as its factorization.

20812864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325213 (or 325203 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 20812864 is about 4562.1117917035. Note that the first 3 decimals coincide. The cubic root of 20812864 is about 275.0704568781.

The spelling of 20812864 in words is "twenty million, eight hundred twelve thousand, eight hundred sixty-four".