21130806256560 has 1920 divisors, whose sum is σ = 97667844857856. Its totient is φ = 3952168796160.

The previous prime is 21130806256543. The next prime is 21130806256597. The reversal of 21130806256560 is 6565260803112.

21130806256560 is a `hidden beast` number, since 2 + 1 + 1 + 3 + 0 + 80 + 6 + 2 + 5 + 6 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 10602510924 + ... + 10602512916.

Almost surely, 2^{21130806256560} is an apocalyptic number.

21130806256560 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 21130806256560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48833922428928).

21130806256560 is an abundant number, since it is smaller than the sum of its proper divisors (76537038601296).

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

21130806256560 is a wasteful number, since it uses less digits than its factorization.

21130806256560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2403 (or 2394 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 21130806256560 in words is "twenty-one trillion, one hundred thirty billion, eight hundred six million, two hundred fifty-six thousand, five hundred sixty".