21675437168 has 40 divisors (see below), whose sum is σ = 52358851200. Its totient is φ = 8444975040.

The previous prime is 21675437167. The next prime is 21675437171. The reversal of 21675437168 is 86173457612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21675437167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8795618 + ... + 8798081.

It is an arithmetic number, because the mean of its divisors is an integer number (1308971280).

Almost surely, 2^21675437168 is an apocalyptic number.

21675437168 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21675437168 is an abundant number, since it is smaller than the sum of its proper divisors (30683414032).

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

21675437168 is a wasteful number, since it uses less digits than its factorization.

21675437168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17593725 (or 17593719 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 50.

The spelling of 21675437168 in words is "twenty-one billion, six hundred seventy-five million, four hundred thirty-seven thousand, one hundred sixty-eight".