13660561645920 has 576 divisors, whose sum is σ = 56498269201920. Its totient is φ = 2934148644864.

The previous prime is 13660561645901. The next prime is 13660561645943. The reversal of 13660561645920 is 2954616506631.

13660561645920 is a `hidden beast` number, since 1 + 3 + 6 + 6 + 0 + 561 + 6 + 4 + 59 + 20 = 666.

It is a super-2 number, since 2×13660561645920² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 110122491 + ... + 110246469.

It is an arithmetic number, because the mean of its divisors is an integer number (98087272920).

Almost surely, 2^{13660561645920} is an apocalyptic number.

13660561645920 is a gapful number since it is divisible by the number (10) 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 13660561645920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28249134600960).

13660561645920 is an abundant number, since it is smaller than the sum of its proper divisors (42837707556000).

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

13660561645920 is a wasteful number, since it uses less digits than its factorization.

13660561645920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124667 (or 124656 counting only the distinct ones).

The product of its (nonzero) digits is 6998400, while the sum is 54.

The spelling of 13660561645920 in words is "thirteen trillion, six hundred sixty billion, five hundred sixty-one million, six hundred forty-five thousand, nine hundred twenty".