21778925716 has 12 divisors (see below), whose sum is σ = 38595565120. Its totient is φ = 10751621400.

The previous prime is 21778925713. The next prime is 21778925737. The reversal of 21778925716 is 61752987712.

It is a super-2 number, since 2×21778925716² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21778925711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34460010 + ... + 34460641.

Almost surely, 2^21778925716 is an apocalyptic number.

It is an amenable number.

21778925716 is a deficient number, since it is larger than the sum of its proper divisors (16816639404).

21778925716 is a wasteful number, since it uses less digits than its factorization.

21778925716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68920734 (or 68920732 counting only the distinct ones).

The product of its digits is 2963520, while the sum is 55.

The spelling of 21778925716 in words is "twenty-one billion, seven hundred seventy-eight million, nine hundred twenty-five thousand, seven hundred sixteen".