21688796484 has 36 divisors (see below), whose sum is σ = 54876226860. Its totient is φ = 7222772160.

The previous prime is 21688796453. The next prime is 21688796489. The reversal of 21688796484 is 48469788612.

21688796484 is a `hidden beast` number, since 2 + 1 + 6 + 88 + 79 + 6 + 484 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18257414400 + 3431382084 = 135120^2 + 58578^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21688796489) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 245719 + ... + 322110.

It is an arithmetic number, because the mean of its divisors is an integer number (1524339635).

Almost surely, 2^21688796484 is an apocalyptic number.

It is an amenable number.

21688796484 is an abundant number, since it is smaller than the sum of its proper divisors (33187430376).

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

21688796484 is a wasteful number, since it uses less digits than its factorization.

21688796484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568900 (or 568895 counting only the distinct ones).

The product of its digits is 37158912, while the sum is 63.

The spelling of 21688796484 in words is "twenty-one billion, six hundred eighty-eight million, seven hundred ninety-six thousand, four hundred eighty-four".