21963408 has 20 divisors (see below), whose sum is σ = 56738928. Its totient is φ = 7321120.

The previous prime is 21963379. The next prime is 21963433. The reversal of 21963408 is 80436912.

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, 228738 + ... + 228833.

Almost surely, 2^21963408 is an apocalyptic number.

It is an amenable number.

21963408 is an abundant number, since it is smaller than the sum of its proper divisors (34775520).

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

21963408 is a wasteful number, since it uses less digits than its factorization.

21963408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457582 (or 457576 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21963408 is about 4686.5134161763. The cubic root of 21963408 is about 280.0484950017.

The spelling of 21963408 in words is "twenty-one million, nine hundred sixty-three thousand, four hundred eight".