20904768 has 42 divisors (see below), whose sum is σ = 59921394. Its totient is φ = 6968064.

The previous prime is 20904733. The next prime is 20904773. The reversal of 20904768 is 86740902.

It can be written as a sum of positive squares in only one way, i.e., 11614464 + 9290304 = 3408^2 + 3048^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17571 + ... + 18722.

Almost surely, 2^20904768 is an apocalyptic number.

It is an amenable number.

20904768 is an abundant number, since it is smaller than the sum of its proper divisors (39016626).

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

20904768 is a wasteful number, since it uses less digits than its factorization.

20904768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36311 (or 36298 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20904768 is about 4572.1732250649. The cubic root of 20904768 is about 275.4747413995.

The spelling of 20904768 in words is "twenty million, nine hundred four thousand, seven hundred sixty-eight".