21425928 has 16 divisors (see below), whose sum is σ = 53564880. Its totient is φ = 7141968.

The previous prime is 21425893. The next prime is 21425993. The reversal of 21425928 is 82952412.

It is a super-2 number, since 2×21425928² = 918140781322368, which contains 22 as substring.

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, 446350 + ... + 446397.

It is an arithmetic number, because the mean of its divisors is an integer number (3347805).

Almost surely, 2^21425928 is an apocalyptic number.

It is an amenable number.

21425928 is an abundant number, since it is smaller than the sum of its proper divisors (32138952).

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

21425928 is a wasteful number, since it uses less digits than its factorization.

21425928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892756 (or 892752 counting only the distinct ones).

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

The square root of 21425928 is about 4628.8149671379. The cubic root of 21425928 is about 277.7451903223.

The spelling of 21425928 in words is "twenty-one million, four hundred twenty-five thousand, nine hundred twenty-eight".