21214656 has 56 divisors (see below), whose sum is σ = 62372240. Its totient is φ = 7070976.

The previous prime is 21214651. The next prime is 21214667. The reversal of 21214656 is 65641212.

21214656 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 4 + 656 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21214651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4411 + ... + 7866.

It is an arithmetic number, because the mean of its divisors is an integer number (1113790).

Almost surely, 2^21214656 is an apocalyptic number.

It is an amenable number.

21214656 is an abundant number, since it is smaller than the sum of its proper divisors (41157584).

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

21214656 is a wasteful number, since it uses less digits than its factorization.

21214656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12298 (or 12282 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 21214656 is about 4605.9370382149. The cubic root of 21214656 is about 276.8292639492.

Adding to 21214656 its reverse (65641212), we get a palindrome (86855868).

The spelling of 21214656 in words is "twenty-one million, two hundred fourteen thousand, six hundred fifty-six".