21630936 has 32 divisors (see below), whose sum is σ = 57259440. Its totient is φ = 6786048.

The previous prime is 21630923. The next prime is 21630991. The reversal of 21630936 is 63903612.

21630936 = 1120² + 1121² + ... + 1136².

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, 26101 + ... + 26916.

Almost surely, 2^21630936 is an apocalyptic number.

It is an amenable number.

21630936 is an abundant number, since it is smaller than the sum of its proper divisors (35628504).

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

21630936 is a wasteful number, since it uses less digits than its factorization.

21630936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53043 (or 53039 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 21630936 is about 4650.9070083157. The cubic root of 21630936 is about 278.6282223266.

The spelling of 21630936 in words is "twenty-one million, six hundred thirty thousand, nine hundred thirty-six".