21621530360610 has 144 divisors (see below), whose sum is σ = 58150106429688. Its totient is φ = 5573773969920.

The previous prime is 21621530360609. The next prime is 21621530360623. The reversal of 21621530360610 is 1606303512612.

21621530360610 is a `hidden beast` number, since 2 + 1 + 6 + 2 + 1 + 5 + 3 + 0 + 36 + 0 + 610 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 17585131932369 + 4036398428241 = 4193463^2 + 2009079^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 80907732 + ... + 81174528.

Almost surely, 2^{21621530360610} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21621530360610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29075053214844).

21621530360610 is an abundant number, since it is smaller than the sum of its proper divisors (36528576069078).

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

21621530360610 is a wasteful number, since it uses less digits than its factorization.

21621530360610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267809 (or 267775 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The spelling of 21621530360610 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred thirty million, three hundred sixty thousand, six hundred ten".