21660536524620 has 192 divisors, whose sum is σ = 70492564832256. Its totient is φ = 4867178346240.

The previous prime is 21660536524619. The next prime is 21660536524643. The reversal of 21660536524620 is 2642563506612.

It is a super-2 number, since 2×21660536524620² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21660536524620.

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, 9300889 + ... + 11394191.

It is an arithmetic number, because the mean of its divisors is an integer number (367148775168).

Almost surely, 2^{21660536524620} is an apocalyptic number.

21660536524620 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 21660536524620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35246282416128).

21660536524620 is an abundant number, since it is smaller than the sum of its proper divisors (48832028307636).

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

21660536524620 is a wasteful number, since it uses less digits than its factorization.

21660536524620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2093740 (or 2093738 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 21660536524620 in words is "twenty-one trillion, six hundred sixty billion, five hundred thirty-six million, five hundred twenty-four thousand, six hundred twenty".