21969225 has 60 divisors (see below), whose sum is σ = 42911440. Its totient is φ = 11080800.

The previous prime is 21969223. The next prime is 21969229. The reversal of 21969225 is 52296912.

It is a happy number.

It is not a de Polignac number, because 21969225 - 2¹ = 21969223 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21969225.

It is not an unprimeable number, because it can be changed into a prime (21969221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 38190 + ... + 38760.

Almost surely, 2^21969225 is an apocalyptic number.

21969225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21969225 is a deficient number, since it is larger than the sum of its proper divisors (20942215).

21969225 is a wasteful number, since it uses less digits than its factorization.

21969225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612 (or 598 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 21969225 is about 4687.1339857102. The cubic root of 21969225 is about 280.0732163974.

The spelling of 21969225 in words is "twenty-one million, nine hundred sixty-nine thousand, two hundred twenty-five".