21916464 has 40 divisors (see below), whose sum is σ = 56788032. Its totient is φ = 7283520.

The previous prime is 21916459. The next prime is 21916483. The reversal of 21916464 is 46461912.

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, 26619 + ... + 27429.

Almost surely, 2^21916464 is an apocalyptic number.

21916464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21916464 is an abundant number, since it is smaller than the sum of its proper divisors (34871568).

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

21916464 is a wasteful number, since it uses less digits than its factorization.

21916464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1385 (or 1379 counting only the distinct ones).

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

The square root of 21916464 is about 4681.5023229728. The cubic root of 21916464 is about 279.8488299637.

The spelling of 21916464 in words is "twenty-one million, nine hundred sixteen thousand, four hundred sixty-four".