21597128748 has 36 divisors (see below), whose sum is σ = 58792185088. Its totient is φ = 6645270240.

The previous prime is 21597128699. The next prime is 21597128759. The reversal of 21597128748 is 84782179512.

21597128748 is a `hidden beast` number, since 2 + 1 + 597 + 1 + 2 + 8 + 7 + 48 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21597128694 and 21597128703.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23073388 + ... + 23074323.

Almost surely, 2^21597128748 is an apocalyptic number.

It is an amenable number.

21597128748 is an abundant number, since it is smaller than the sum of its proper divisors (37195056340).

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

21597128748 is a wasteful number, since it uses less digits than its factorization.

21597128748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46147734 (or 46147729 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 54.

The spelling of 21597128748 in words is "twenty-one billion, five hundred ninety-seven million, one hundred twenty-eight thousand, seven hundred forty-eight".