21572324 has 12 divisors (see below), whose sum is σ = 37784124. Its totient is φ = 10776864.

The previous prime is 21572297. The next prime is 21572333. The reversal of 21572324 is 42327512.

It can be written as a sum of positive squares in 2 ways, for example, as 20994724 + 577600 = 4582^2 + 760^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21572293 and 21572302.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7634 + ... + 10070.

It is an arithmetic number, because the mean of its divisors is an integer number (3148677).

Almost surely, 2^21572324 is an apocalyptic number.

It is an amenable number.

21572324 is a deficient number, since it is larger than the sum of its proper divisors (16211800).

21572324 is a wasteful number, since it uses less digits than its factorization.

21572324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4654 (or 4652 counting only the distinct ones).

The product of its digits is 3360, while the sum is 26.

The square root of 21572324 is about 4644.6015975539. The cubic root of 21572324 is about 278.3763341677.

Adding to 21572324 its reverse (42327512), we get a palindrome (63899836).

The spelling of 21572324 in words is "twenty-one million, five hundred seventy-two thousand, three hundred twenty-four".