21312752 has 10 divisors (see below), whose sum is σ = 41293488. Its totient is φ = 10656368.

The previous prime is 21312751. The next prime is 21312763. The reversal of 21312752 is 25721312.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312751) 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, 666008 + ... + 666039.

Almost surely, 2^21312752 is an apocalyptic number.

It is an amenable number.

21312752 is a deficient number, since it is larger than the sum of its proper divisors (19980736).

21312752 is a wasteful number, since it uses less digits than its factorization.

21312752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1332055 (or 1332049 counting only the distinct ones).

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

The square root of 21312752 is about 4616.5736212044. The cubic root of 21312752 is about 277.2552916711.

The spelling of 21312752 in words is "twenty-one million, three hundred twelve thousand, seven hundred fifty-two".