21567225 has 24 divisors (see below), whose sum is σ = 35935200. Its totient is φ = 11413120.

The previous prime is 21567191. The next prime is 21567229. The reversal of 21567225 is 52276512.

It is not a de Polignac number, because 21567225 - 2¹⁰ = 21566201 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21567192 and 21567201.

It is not an unprimeable number, because it can be changed into a prime (21567229) 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 23 ways as a sum of consecutive naturals, for example, 9226 + ... + 11324.

It is an arithmetic number, because the mean of its divisors is an integer number (1497300).

Almost surely, 2^21567225 is an apocalyptic number.

21567225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21567225 is a deficient number, since it is larger than the sum of its proper divisors (14367975).

21567225 is a wasteful number, since it uses less digits than its factorization.

21567225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2249 (or 2244 counting only the distinct ones).

The product of its digits is 8400, while the sum is 30.

The square root of 21567225 is about 4644.0526482804. The cubic root of 21567225 is about 278.3543993840.

The spelling of 21567225 in words is "twenty-one million, five hundred sixty-seven thousand, two hundred twenty-five".