21485904 has 40 divisors (see below), whose sum is σ = 60552672. Its totient is φ = 6510720.

The previous prime is 21485899. The next prime is 21485911. The reversal of 21485904 is 40958412.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19819 + ... + 20874.

Almost surely, 2^21485904 is an apocalyptic number.

21485904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21485904 is an abundant number, since it is smaller than the sum of its proper divisors (39066768).

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

21485904 is a wasteful number, since it uses less digits than its factorization.

21485904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40715 (or 40709 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21485904 is about 4635.2889877547. The cubic root of 21485904 is about 278.0041060070.

The spelling of 21485904 in words is "twenty-one million, four hundred eighty-five thousand, nine hundred four".