21715685268850 has 24 divisors (see below), whose sum is σ = 40457065643460. Its totient is φ = 8672103990720.

The previous prime is 21715685268821. The next prime is 21715685268911. The reversal of 21715685268850 is 5886258651712.

It can be written as a sum of positive squares in 6 ways, for example, as 4619056341601 + 17096628927249 = 2149199^2 + 4134807^2 .

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, 354221965 + ... + 354283264.

Almost surely, 2^{21715685268850} is an apocalyptic number.

21715685268850 is a deficient number, since it is larger than the sum of its proper divisors (18741380374610).

21715685268850 is a wasteful number, since it uses less digits than its factorization.

21715685268850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708505854 (or 708505849 counting only the distinct ones).

The product of its (nonzero) digits is 64512000, while the sum is 64.

The spelling of 21715685268850 in words is "twenty-one trillion, seven hundred fifteen billion, six hundred eighty-five million, two hundred sixty-eight thousand, eight hundred fifty".