21755928672 has 60 divisors (see below), whose sum is σ = 63983589516. Its totient is φ = 7251975360.

The previous prime is 21755928671. The next prime is 21755928707. The reversal of 21755928672 is 27682955712.

21755928672 is a `hidden beast` number, since 2 + 1 + 7 + 559 + 2 + 86 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755928671) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4194154 + ... + 4199337.

Almost surely, 2^21755928672 is an apocalyptic number.

It is an amenable number.

21755928672 is an abundant number, since it is smaller than the sum of its proper divisors (42227660844).

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

21755928672 is an equidigital number, since it uses as much as digits as its factorization.

21755928672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8393513 (or 8393496 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 54.

The spelling of 21755928672 in words is "twenty-one billion, seven hundred fifty-five million, nine hundred twenty-eight thousand, six hundred seventy-two".