21223625 has 8 divisors (see below), whose sum is σ = 26487240. Its totient is φ = 16978800.

The previous prime is 21223619. The next prime is 21223637. The reversal of 21223625 is 52632212.

It can be written as a sum of positive squares in 4 ways, for example, as 466489 + 20757136 = 683^2 + 4556^2 .

It is not a de Polignac number, because 21223625 - 2⁸ = 21223369 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21223625.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84770 + ... + 85019.

It is an arithmetic number, because the mean of its divisors is an integer number (3310905).

Almost surely, 2^21223625 is an apocalyptic number.

21223625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21223625 is a deficient number, since it is larger than the sum of its proper divisors (5263615).

21223625 is an equidigital number, since it uses as much as digits as its factorization.

21223625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169804 (or 169794 counting only the distinct ones).

The product of its digits is 1440, while the sum is 23.

The square root of 21223625 is about 4606.9105700024. The cubic root of 21223625 is about 276.8682705028.

Adding to 21223625 its reverse (52632212), we get a palindrome (73855837).

The spelling of 21223625 in words is "twenty-one million, two hundred twenty-three thousand, six hundred twenty-five".