15661645349376 has 320 divisors, whose sum is σ = 45899924716800. Its totient is φ = 4716076400640.

The previous prime is 15661645349359. The next prime is 15661645349401. The reversal of 15661645349376 is 67394354616651.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 242359246 + ... + 242423858.

It is an arithmetic number, because the mean of its divisors is an integer number (143437264740).

Almost surely, 2^{15661645349376} is an apocalyptic number.

15661645349376 is a gapful number since it is divisible by the number (16) 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 15661645349376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22949962358400).

15661645349376 is an abundant number, since it is smaller than the sum of its proper divisors (30238279367424).

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

15661645349376 is a wasteful number, since it uses less digits than its factorization.

15661645349376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64907 (or 64891 counting only the distinct ones).

The product of its digits is 293932800, while the sum is 66.

The spelling of 15661645349376 in words is "fifteen trillion, six hundred sixty-one billion, six hundred forty-five million, three hundred forty-nine thousand, three hundred seventy-six".