21708534860 has 36 divisors (see below), whose sum is σ = 46727015664. Its totient is φ = 8471610240.

The previous prime is 21708534857. The next prime is 21708534877. The reversal of 21708534860 is 6843580712.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 289232 + ... + 356471.

Almost surely, 2^21708534860 is an apocalyptic number.

21708534860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21708534860 is an abundant number, since it is smaller than the sum of its proper divisors (25018480804).

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

21708534860 is a wasteful number, since it uses less digits than its factorization.

21708534860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645794 (or 645751 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 44.

The spelling of 21708534860 in words is "twenty-one billion, seven hundred eight million, five hundred thirty-four thousand, eight hundred sixty".