21424173264 has 90 divisors (see below), whose sum is σ = 64924932150. Its totient is φ = 6592045824.

The previous prime is 21424173259. The next prime is 21424173283. The reversal of 21424173264 is 46237142412.

21424173264 is a `hidden beast` number, since 2 + 1 + 424 + 173 + 2 + 64 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 445547664 + 20978625600 = 21108^2 + 144840^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 415839 + ... + 464510.

It is an arithmetic number, because the mean of its divisors is an integer number (721388135).

Almost surely, 2^21424173264 is an apocalyptic number.

21424173264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21424173264 is an abundant number, since it is smaller than the sum of its proper divisors (43500758886).

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

21424173264 is a wasteful number, since it uses less digits than its factorization.

21424173264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880389 (or 880367 counting only the distinct ones).

The product of its digits is 64512, while the sum is 36.

The spelling of 21424173264 in words is "twenty-one billion, four hundred twenty-four million, one hundred seventy-three thousand, two hundred sixty-four".