21195397565964 has 18 divisors (see below), whose sum is σ = 53577254958500. Its totient is φ = 7065132521976.

The previous prime is 21195397565941. The next prime is 21195397565971. The reversal of 21195397565964 is 46956579359112.

21195397565964 is a `hidden beast` number, since 2 + 1 + 1 + 9 + 53 + 9 + 7 + 565 + 9 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a junction number, because it is equal to n+sod(n) for n = 21195397565892 and 21195397565901.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 294380521714 + ... + 294380521785.

Almost surely, 2^{21195397565964} is an apocalyptic number.

It is an amenable number.

21195397565964 is an abundant number, since it is smaller than the sum of its proper divisors (32381857392536).

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

21195397565964 is a wasteful number, since it uses less digits than its factorization.

21195397565964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588761043509 (or 588761043504 counting only the distinct ones).

The product of its digits is 551124000, while the sum is 72.

The spelling of 21195397565964 in words is "twenty-one trillion, one hundred ninety-five billion, three hundred ninety-seven million, five hundred sixty-five thousand, nine hundred sixty-four".