21925172 has 12 divisors (see below), whose sum is σ = 40626180. Its totient is φ = 10317696.

The previous prime is 21925159. The next prime is 21925219. The reversal of 21925172 is 27152912.

It can be written as a sum of positive squares in 2 ways, for example, as 5973136 + 15952036 = 2444^2 + 3994^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161147 + ... + 161282.

It is an arithmetic number, because the mean of its divisors is an integer number (3385515).

Almost surely, 2^21925172 is an apocalyptic number.

It is an amenable number.

21925172 is a deficient number, since it is larger than the sum of its proper divisors (18701008).

21925172 is a wasteful number, since it uses less digits than its factorization.

21925172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322450 (or 322448 counting only the distinct ones).

The product of its digits is 2520, while the sum is 29.

The square root of 21925172 is about 4682.4322739363. The cubic root of 21925172 is about 279.8858888757.

The spelling of 21925172 in words is "twenty-one million, nine hundred twenty-five thousand, one hundred seventy-two".