21694624 has 24 divisors (see below), whose sum is σ = 48813408. Its totient is φ = 9297600.

The previous prime is 21694613. The next prime is 21694627. The reversal of 21694624 is 42649612.

It is a self number, because there is not a number n which added to its sum of digits gives 21694624.

It is not an unprimeable number, because it can be changed into a prime (21694627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48202 + ... + 48649.

It is an arithmetic number, because the mean of its divisors is an integer number (2033892).

Almost surely, 2^21694624 is an apocalyptic number.

It is an amenable number.

21694624 is an abundant number, since it is smaller than the sum of its proper divisors (27118784).

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

21694624 is an equidigital number, since it uses as much as digits as its factorization.

21694624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96868 (or 96860 counting only the distinct ones).

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

The square root of 21694624 is about 4657.7488124629. The cubic root of 21694624 is about 278.9014095625.

The spelling of 21694624 in words is "twenty-one million, six hundred ninety-four thousand, six hundred twenty-four".