21656862 has 16 divisors (see below), whose sum is σ = 48126480. Its totient is φ = 7218936.

The previous prime is 21656857. The next prime is 21656863. The reversal of 21656862 is 26865612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21656863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 200473 + ... + 200580.

It is an arithmetic number, because the mean of its divisors is an integer number (3007905).

Almost surely, 2^21656862 is an apocalyptic number.

21656862 is an abundant number, since it is smaller than the sum of its proper divisors (26469618).

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

21656862 is a wasteful number, since it uses less digits than its factorization.

21656862 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401064 (or 401058 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 21656862 is about 4653.6933719359. The cubic root of 21656862 is about 278.7394955388.

The spelling of 21656862 in words is "twenty-one million, six hundred fifty-six thousand, eight hundred sixty-two".