21625656 has 32 divisors (see below), whose sum is σ = 58223760. Its totient is φ = 6653952.

The previous prime is 21625633. The next prime is 21625661. The reversal of 21625656 is 65652612.

It is a happy number.

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, 34345 + ... + 34968.

Almost surely, 2^21625656 is an apocalyptic number.

21625656 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21625656 is an abundant number, since it is smaller than the sum of its proper divisors (36598104).

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

21625656 is a wasteful number, since it uses less digits than its factorization.

21625656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69335 (or 69331 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 21625656 is about 4650.3393424566. The cubic root of 21625656 is about 278.6055499108.

The spelling of 21625656 in words is "twenty-one million, six hundred twenty-five thousand, six hundred fifty-six".