21642512 has 10 divisors (see below), whose sum is σ = 41932398. Its totient is φ = 10821248.

The previous prime is 21642503. The next prime is 21642527. The reversal of 21642512 is 21524612.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19749136 + 1893376 = 4444^2 + 1376^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 676313 + ... + 676344.

Almost surely, 2^21642512 is an apocalyptic number.

It is an amenable number.

21642512 is a deficient number, since it is larger than the sum of its proper divisors (20289886).

21642512 is a wasteful number, since it uses less digits than its factorization.

21642512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1352665 (or 1352659 counting only the distinct ones).

The product of its digits is 960, while the sum is 23.

The square root of 21642512 is about 4652.1513302987. The cubic root of 21642512 is about 278.6779169724.

The spelling of 21642512 in words is "twenty-one million, six hundred forty-two thousand, five hundred twelve".