21873365568 has 42 divisors (see below), whose sum is σ = 62696054694. Its totient is φ = 7291121664.

The previous prime is 21873365509. The next prime is 21873365587. The reversal of 21873365568 is 86556337812.

21873365568 is a `hidden beast` number, since 2 + 1 + 8 + 73 + 3 + 6 + 5 + 568 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21736194624 + 137170944 = 147432^2 + 11712^2 .

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, 18986721 + ... + 18987872.

It is an arithmetic number, because the mean of its divisors is an integer number (1492763207).

Almost surely, 2^21873365568 is an apocalyptic number.

It is an amenable number.

21873365568 is an abundant number, since it is smaller than the sum of its proper divisors (40822689126).

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

21873365568 is a wasteful number, since it uses less digits than its factorization.

21873365568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37974611 (or 37974598 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 54.

The spelling of 21873365568 in words is "twenty-one billion, eight hundred seventy-three million, three hundred sixty-five thousand, five hundred sixty-eight".