21507982336 has 33 divisors (see below), whose sum is σ = 43004344231. Its totient is φ = 10751644672.

The previous prime is 21507982333. The next prime is 21507982381. The reversal of 21507982336 is 63328970512.

The square root of 21507982336 is 146656.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21507982333) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4690701 + ... + 4695283.

Almost surely, 2^21507982336 is an apocalyptic number.

21507982336 is the 146656-th square number.

It is an amenable number.

21507982336 is a deficient number, since it is larger than the sum of its proper divisors (21496361895).

21507982336 is an frugal number, since it uses more digits than its factorization.

21507982336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9186 (or 4585 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 46.

The spelling of 21507982336 in words is "twenty-one billion, five hundred seven million, nine hundred eighty-two thousand, three hundred thirty-six".