21963844 has 12 divisors (see below), whose sum is σ = 43927744. Its totient is φ = 9413064.

The previous prime is 21963833. The next prime is 21963863. The reversal of 21963844 is 44836912.

21963844 is an admirable number.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

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, 392184 + ... + 392239.

Almost surely, 2^21963844 is an apocalyptic number.

It is an amenable number.

21963844 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21963844 is a wasteful number, since it uses less digits than its factorization.

21963844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784434 (or 784432 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 21963844 is about 4686.5599324024. The cubic root of 21963844 is about 280.0503480890.

The spelling of 21963844 in words is "twenty-one million, nine hundred sixty-three thousand, eight hundred forty-four".