20867904 has 42 divisors (see below), whose sum is σ = 59815730. Its totient is φ = 6955776.

The previous prime is 20867879. The next prime is 20867911. The reversal of 20867904 is 40976802.

It can be written as a sum of positive squares in only one way, i.e., 18045504 + 2822400 = 4248^2 + 1680^2 .

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, 17539 + ... + 18690.

Almost surely, 2^20867904 is an apocalyptic number.

20867904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20867904 is an abundant number, since it is smaller than the sum of its proper divisors (38947826).

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

20867904 is a wasteful number, since it uses less digits than its factorization.

20867904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36247 (or 36234 counting only the distinct ones).

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

The square root of 20867904 is about 4568.1401029303. The cubic root of 20867904 is about 275.3127197341.

The spelling of 20867904 in words is "twenty million, eight hundred sixty-seven thousand, nine hundred four".