21632812 has 12 divisors (see below), whose sum is σ = 37922920. Its totient is φ = 10797696.

The previous prime is 21632801. The next prime is 21632813. The reversal of 21632812 is 21823612.

It is not an unprimeable number, because it can be changed into a prime (21632813) 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 in 3 ways as a sum of consecutive naturals, for example, 1893 + ... + 6844.

Almost surely, 2^21632812 is an apocalyptic number.

It is an amenable number.

21632812 is a deficient number, since it is larger than the sum of its proper divisors (16290108).

21632812 is a wasteful number, since it uses less digits than its factorization.

21632812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9360 (or 9358 counting only the distinct ones).

The product of its digits is 1152, while the sum is 25.

The square root of 21632812 is about 4651.1086850341. The cubic root of 21632812 is about 278.6362770164.

The spelling of 21632812 in words is "twenty-one million, six hundred thirty-two thousand, eight hundred twelve".