21959964 has 48 divisors (see below), whose sum is σ = 61316640. Its totient is φ = 6756480.

The previous prime is 21959957. The next prime is 21960007. The reversal of 21959964 is 46995912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6417 + ... + 9224.

It is an arithmetic number, because the mean of its divisors is an integer number (1277430).

Almost surely, 2^21959964 is an apocalyptic number.

It is an amenable number.

21959964 is an abundant number, since it is smaller than the sum of its proper divisors (39356676).

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

21959964 is a wasteful number, since it uses less digits than its factorization.

21959964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15667 (or 15659 counting only the distinct ones).

The product of its digits is 174960, while the sum is 45.

The square root of 21959964 is about 4686.1459644360. The cubic root of 21959964 is about 280.0338564503.

The spelling of 21959964 in words is "twenty-one million, nine hundred fifty-nine thousand, nine hundred sixty-four".