21260611512 has 256 divisors, whose sum is σ = 68578099200. Its totient is φ = 5977722240.

The previous prime is 21260611397. The next prime is 21260611523. The reversal of 21260611512 is 21511606212.

21260611512 is a `hidden beast` number, since 2 + 1 + 2 + 606 + 1 + 1 + 51 + 2 = 666.

It is a super-2 number, since 2×21260611512² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 32859973 + ... + 32860619.

It is an arithmetic number, because the mean of its divisors is an integer number (267883200).

Almost surely, 2^21260611512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21260611512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34289049600).

21260611512 is an abundant number, since it is smaller than the sum of its proper divisors (47317487688).

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

21260611512 is a wasteful number, since it uses less digits than its factorization.

21260611512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 21260611512 in words is "twenty-one billion, two hundred sixty million, six hundred eleven thousand, five hundred twelve".