21823904 has 12 divisors (see below), whose sum is σ = 42965874. Its totient is φ = 10911936.

The previous prime is 21823897. The next prime is 21823981. The reversal of 21823904 is 40932812.

It can be written as a sum of positive squares in only one way, i.e., 13690000 + 8133904 = 3700^2 + 2852^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340967 + ... + 341030.

Almost surely, 2^21823904 is an apocalyptic number.

It is an amenable number.

21823904 is a deficient number, since it is larger than the sum of its proper divisors (21141970).

21823904 is an equidigital number, since it uses as much as digits as its factorization.

21823904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682007 (or 681999 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21823904 is about 4671.6061477826. The cubic root of 21823904 is about 279.4543113545.

The spelling of 21823904 in words is "twenty-one million, eight hundred twenty-three thousand, nine hundred four".