21758946816 has 80 divisors (see below), whose sum is σ = 61377102864. Its totient is φ = 6826328064.

The previous prime is 21758946787. The next prime is 21758946829. The reversal of 21758946816 is 61864985712.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 390535 + ... + 442758.

Almost surely, 2^21758946816 is an apocalyptic number.

It is an amenable number.

21758946816 is an abundant number, since it is smaller than the sum of its proper divisors (39618156048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21758946816 is an equidigital number, since it uses as much as digits as its factorization.

21758946816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833331 (or 833315 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 57.

The spelling of 21758946816 in words is "twenty-one billion, seven hundred fifty-eight million, nine hundred forty-six thousand, eight hundred sixteen".