21768755984 has 20 divisors (see below), whose sum is σ = 42179907084. Its totient is φ = 10883618688.

The previous prime is 21768755971. The next prime is 21768755993. The reversal of 21768755984 is 48955786712.

It can be written as a sum of positive squares in 2 ways, for example, as 6336160000 + 15432595984 = 79600^2 + 124228^2 .

It is a Smith number, since the sum of its digits (62) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242894 + ... + 320210.

Almost surely, 2^21768755984 is an apocalyptic number.

It is an amenable number.

21768755984 is a deficient number, since it is larger than the sum of its proper divisors (20411151100).

21768755984 is a wasteful number, since it uses less digits than its factorization.

21768755984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94922 (or 94916 counting only the distinct ones).

The product of its digits is 33868800, while the sum is 62.

The spelling of 21768755984 in words is "twenty-one billion, seven hundred sixty-eight million, seven hundred fifty-five thousand, nine hundred eighty-four".