21782768816 has 20 divisors (see below), whose sum is σ = 42208084224. Its totient is φ = 10890360000.

The previous prime is 21782768807. The next prime is 21782768827. The reversal of 21782768816 is 61886728712.

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, 129041 + ... + 245391.

Almost surely, 2^21782768816 is an apocalyptic number.

It is an amenable number.

21782768816 is a deficient number, since it is larger than the sum of its proper divisors (20425315408).

21782768816 is a wasteful number, since it uses less digits than its factorization.

21782768816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128060 (or 128054 counting only the distinct ones).

The product of its digits is 3612672, while the sum is 56.

The spelling of 21782768816 in words is "twenty-one billion, seven hundred eighty-two million, seven hundred sixty-eight thousand, eight hundred sixteen".