21873615624 has 512 divisors, whose sum is σ = 76949913600. Its totient is φ = 5613649920.

The previous prime is 21873615541. The next prime is 21873615649. The reversal of 21873615624 is 42651637812.

21873615624 is a `hidden beast` number, since 2 + 1 + 8 + 7 + 3 + 6 + 15 + 624 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21873615624.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 77291787 + ... + 77292069.

It is an arithmetic number, because the mean of its divisors is an integer number (150292800).

Almost surely, 2^21873615624 is an apocalyptic number.

21873615624 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 21873615624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38474956800).

21873615624 is an abundant number, since it is smaller than the sum of its proper divisors (55076297976).

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

21873615624 is a wasteful number, since it uses less digits than its factorization.

21873615624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450 (or 440 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 21873615624 in words is "twenty-one billion, eight hundred seventy-three million, six hundred fifteen thousand, six hundred twenty-four".