21478604 has 12 divisors (see below), whose sum is σ = 42957264. Its totient is φ = 9205104.

The previous prime is 21478579. The next prime is 21478627. The reversal of 21478604 is 40687412.

21478604 is an admirable number.

It is a super-2 number, since 2×21478604² = 922660859577632, which contains 22 as substring.

It is a plaindrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 383519 + ... + 383574.

It is an arithmetic number, because the mean of its divisors is an integer number (3579772).

Almost surely, 2^21478604 is an apocalyptic number.

It is an amenable number.

21478604 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21478604 is a wasteful number, since it uses less digits than its factorization.

21478604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767104 (or 767102 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 21478604 is about 4634.5014834392. The cubic root of 21478604 is about 277.9726177678.

The spelling of 21478604 in words is "twenty-one million, four hundred seventy-eight thousand, six hundred four".