123721856565660 has 36 divisors (see below), whose sum is σ = 375289631583048. Its totient is φ = 32992495084128.

The previous prime is 123721856565623. The next prime is 123721856565677. The reversal of 123721856565660 is 66565658127321.

123721856565660 is a `hidden beast` number, since 1 + 2 + 3 + 7 + 2 + 1 + 8 + 5 + 6 + 565 + 6 + 60 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 343671823614 + ... + 343671823973.

It is an arithmetic number, because the mean of its divisors is an integer number (10424711988418).

Almost surely, 2^{123721856565660} is an apocalyptic number.

123721856565660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123721856565660 is an abundant number, since it is smaller than the sum of its proper divisors (251567775017388).

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

123721856565660 is a wasteful number, since it uses less digits than its factorization.

123721856565660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687343647602 (or 687343647597 counting only the distinct ones).

The product of its (nonzero) digits is 108864000, while the sum is 63.

The spelling of 123721856565660 in words is "one hundred twenty-three trillion, seven hundred twenty-one billion, eight hundred fifty-six million, five hundred sixty-five thousand, six hundred sixty".