21574516464 has 120 divisors (see below), whose sum is σ = 62645311872. Its totient is φ = 6923911680.

The previous prime is 21574516441. The next prime is 21574516477. The reversal of 21574516464 is 46461547512.

21574516464 is a `hidden beast` number, since 2 + 1 + 5 + 74 + 516 + 4 + 64 = 666.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 867142 + ... + 891674.

Almost surely, 2^21574516464 is an apocalyptic number.

21574516464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21574516464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31322655936).

21574516464 is an abundant number, since it is smaller than the sum of its proper divisors (41070795408).

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

21574516464 is a wasteful number, since it uses less digits than its factorization.

21574516464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24775 (or 24766 counting only the distinct ones).

The product of its digits is 806400, while the sum is 45.

The spelling of 21574516464 in words is "twenty-one billion, five hundred seventy-four million, five hundred sixteen thousand, four hundred sixty-four".