21132572 has 6 divisors (see below), whose sum is σ = 36982008. Its totient is φ = 10566284.

The previous prime is 21132571. The next prime is 21132599. The reversal of 21132572 is 27523112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132571) by changing a digit.

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 as a sum of consecutive naturals, namely, 2641568 + ... + 2641575.

It is an arithmetic number, because the mean of its divisors is an integer number (6163668).

Almost surely, 2^21132572 is an apocalyptic number.

It is an amenable number.

21132572 is a deficient number, since it is larger than the sum of its proper divisors (15849436).

21132572 is a wasteful number, since it uses less digits than its factorization.

21132572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5283147 (or 5283145 counting only the distinct ones).

The product of its digits is 840, while the sum is 23.

The square root of 21132572 is about 4597.0177289195. The cubic root of 21132572 is about 276.4717654429.

Adding to 21132572 its reverse (27523112), we get a palindrome (48655684).

The spelling of 21132572 in words is "twenty-one million, one hundred thirty-two thousand, five hundred seventy-two".