21624625 has 16 divisors (see below), whose sum is σ = 29442816. Its totient is φ = 15726000.

The previous prime is 21624601. The next prime is 21624637. The reversal of 21624625 is 52642612.

It is not a de Polignac number, because 21624625 - 2¹¹ = 21622577 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21624593 and 21624602.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6489 + ... + 9238.

It is an arithmetic number, because the mean of its divisors is an integer number (1840176).

Almost surely, 2^21624625 is an apocalyptic number.

21624625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21624625 is a deficient number, since it is larger than the sum of its proper divisors (7818191).

21624625 is a wasteful number, since it uses less digits than its factorization.

21624625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15753 (or 15743 counting only the distinct ones).

The product of its digits is 5760, while the sum is 28.

The square root of 21624625 is about 4650.2284890100. The cubic root of 21624625 is about 278.6011223474.

The spelling of 21624625 in words is "twenty-one million, six hundred twenty-four thousand, six hundred twenty-five".