21929252 has 24 divisors (see below), whose sum is σ = 40864824. Its totient is φ = 10260992.

The previous prime is 21929233. The next prime is 21929263. The reversal of 21929252 is 25292912.

It can be written as a sum of positive squares in 4 ways, for example, as 6120676 + 15808576 = 2474^2 + 3976^2 .

It is a congruent number.

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, 12578 + ... + 14214.

It is an arithmetic number, because the mean of its divisors is an integer number (1702701).

Almost surely, 2^21929252 is an apocalyptic number.

It is an amenable number.

21929252 is a deficient number, since it is larger than the sum of its proper divisors (18935572).

21929252 is a wasteful number, since it uses less digits than its factorization.

21929252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1855 (or 1853 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 21929252 is about 4682.8679246803. The cubic root of 21929252 is about 279.9032488854.

The spelling of 21929252 in words is "twenty-one million, nine hundred twenty-nine thousand, two hundred fifty-two".