21968625 has 32 divisors (see below), whose sum is σ = 41783040. Its totient is φ = 10041600.

The previous prime is 21968603. The next prime is 21968633. The reversal of 21968625 is 52686912.

It is not a de Polignac number, because 21968625 - 2²² = 17774321 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1560 + ... + 6809.

It is an arithmetic number, because the mean of its divisors is an integer number (1305720).

Almost surely, 2^21968625 is an apocalyptic number.

21968625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21968625 is a deficient number, since it is larger than the sum of its proper divisors (19814415).

21968625 is an equidigital number, since it uses as much as digits as its factorization.

21968625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8394 (or 8384 counting only the distinct ones).

The product of its digits is 51840, while the sum is 39.

The square root of 21968625 is about 4687.0699802755. The cubic root of 21968625 is about 280.0706666874.

The spelling of 21968625 in words is "twenty-one million, nine hundred sixty-eight thousand, six hundred twenty-five".