21587904000 has 960 divisors, whose sum is σ = 88743695040. Its totient is φ = 5142528000.

The previous prime is 21587903977. The next prime is 21587904043. The reversal of 21587904000 is 40978512.

It is a tau number, because it is divible by the number of its divisors (960).

It is a super-2 number, since 2×21587904000² (a number of 21 digits) contains 22 as substring.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 696383985 + ... + 696384015.

It is an arithmetic number, because the mean of its divisors is an integer number (92441349).

Almost surely, 2^21587904000 is an apocalyptic number.

21587904000 is a gapful number since it is divisible by the number (20) 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 21587904000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44371847520).

21587904000 is an abundant number, since it is smaller than the sum of its proper divisors (67155791040).

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

21587904000 is an equidigital number, since it uses as much as digits as its factorization.

21587904000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 21587904000 in words is "twenty-one billion, five hundred eighty-seven million, nine hundred four thousand".