21331210816 has 28 divisors (see below), whose sum is σ = 42356471040. Its totient is φ = 10658714240.

The previous prime is 21331210793. The next prime is 21331210829. The reversal of 21331210816 is 61801213312.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7120 + ... + 206671.

Almost surely, 2^21331210816 is an apocalyptic number.

It is an amenable number.

21331210816 is a deficient number, since it is larger than the sum of its proper divisors (21025260224).

21331210816 is a wasteful number, since it uses less digits than its factorization.

21331210816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215362 (or 215352 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The spelling of 21331210816 in words is "twenty-one billion, three hundred thirty-one million, two hundred ten thousand, eight hundred sixteen".