21660365434660 has 48 divisors (see below), whose sum is σ = 45623043774000. Its totient is φ = 8638195244544.

The previous prime is 21660365434637. The next prime is 21660365434661. The reversal of 21660365434660 is 6643456306612.

It can be written as a sum of positive squares in 8 ways, for example, as 2021765484544 + 19638599950116 = 1421888^2 + 4431546^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21660365434598 and 21660365434607.

It is not an unprimeable number, because it can be changed into a prime (21660365434661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54448234 + ... + 54844606.

It is an arithmetic number, because the mean of its divisors is an integer number (950480078625).

Almost surely, 2^{21660365434660} is an apocalyptic number.

21660365434660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21660365434660 is an abundant number, since it is smaller than the sum of its proper divisors (23962678339340).

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

21660365434660 is a wasteful number, since it uses less digits than its factorization.

21660365434660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404560 (or 404558 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 52.

The spelling of 21660365434660 in words is "twenty-one trillion, six hundred sixty billion, three hundred sixty-five million, four hundred thirty-four thousand, six hundred sixty".