21656496 has 20 divisors (see below), whose sum is σ = 55946072. Its totient is φ = 7218816.

The previous prime is 21656461. The next prime is 21656513. The reversal of 21656496 is 69465612.

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, 225541 + ... + 225636.

Almost surely, 2^21656496 is an apocalyptic number.

It is an amenable number.

21656496 is an abundant number, since it is smaller than the sum of its proper divisors (34289576).

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

21656496 is a wasteful number, since it uses less digits than its factorization.

21656496 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451188 (or 451182 counting only the distinct ones).

The product of its digits is 77760, while the sum is 39.

The square root of 21656496 is about 4653.6540481647. The cubic root of 21656496 is about 278.7379253016.

The spelling of 21656496 in words is "twenty-one million, six hundred fifty-six thousand, four hundred ninety-six".