21662944 has 12 divisors (see below), whose sum is σ = 42648984. Its totient is φ = 10831456.

The previous prime is 21662939. The next prime is 21662959. The reversal of 21662944 is 44926612.

21662944 = 550² + 551² + ... + 613².

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 338452 + ... + 338515.

It is an arithmetic number, because the mean of its divisors is an integer number (3554082).

Almost surely, 2^21662944 is an apocalyptic number.

It is an amenable number.

21662944 is a deficient number, since it is larger than the sum of its proper divisors (20986040).

21662944 is an equidigital number, since it uses as much as digits as its factorization.

21662944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676977 (or 676969 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 21662944 is about 4654.3467855329. The cubic root of 21662944 is about 278.7655863445.

The spelling of 21662944 in words is "twenty-one million, six hundred sixty-two thousand, nine hundred forty-four".