21512332 has 24 divisors (see below), whose sum is σ = 40140800. Its totient is φ = 10058256.

The previous prime is 21512311. The next prime is 21512333. The reversal of 21512332 is 23321512.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is not an unprimeable number, because it can be changed into a prime (21512333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4213 + ... + 7795.

Almost surely, 2^21512332 is an apocalyptic number.

It is an amenable number.

21512332 is a deficient number, since it is larger than the sum of its proper divisors (18628468).

21512332 is a wasteful number, since it uses less digits than its factorization.

21512332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3685 (or 3683 counting only the distinct ones).

The product of its digits is 360, while the sum is 19.

The square root of 21512332 is about 4638.1388508754. The cubic root of 21512332 is about 278.1180424468.

Adding to 21512332 its reverse (23321512), we get a palindrome (44833844).

The spelling of 21512332 in words is "twenty-one million, five hundred twelve thousand, three hundred thirty-two".