21087977472000 has 480 divisors, whose sum is σ = 76031242115400. Its totient is φ = 5623303372800.

The previous prime is 21087977471987. The next prime is 21087977472011. The reversal of 21087977472000 is 27477978012.

21087977472000 is a `hidden beast` number, since 2 + 1 + 0 + 87 + 97 + 7 + 472 + 0 + 0 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 11202034139136 + 9885943332864 = 3346944^2 + 3144192^2 .

It is a tau number, because it is divible by the number of its divisors (480).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 589806124 + ... + 589841876.

Almost surely, 2^{21087977472000} is an apocalyptic number.

21087977472000 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 21087977472000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38015621057700).

21087977472000 is an abundant number, since it is smaller than the sum of its proper divisors (54943264643400).

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

21087977472000 is an frugal number, since it uses more digits than its factorization.

21087977472000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35812 (or 35763 counting only the distinct ones).

The product of its (nonzero) digits is 2765952, while the sum is 54.

The spelling of 21087977472000 in words is "twenty-one trillion, eighty-seven billion, nine hundred seventy-seven million, four hundred seventy-two thousand".