15661707056 has 80 divisors (see below), whose sum is σ = 32164131840. Its totient is φ = 7376624640.

The previous prime is 15661707037. The next prime is 15661707073. The reversal of 15661707056 is 65070716651.

It is a junction number, because it is equal to n+sod(n) for n = 15661706998 and 15661707016.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3592430 + ... + 3596786.

It is an arithmetic number, because the mean of its divisors is an integer number (402051648).

Almost surely, 2^15661707056 is an apocalyptic number.

15661707056 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 15661707056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16082065920).

15661707056 is an abundant number, since it is smaller than the sum of its proper divisors (16502424784).

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

15661707056 is a wasteful number, since it uses less digits than its factorization.

15661707056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4582 (or 4576 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 44.

The spelling of 15661707056 in words is "fifteen billion, six hundred sixty-one million, seven hundred seven thousand, fifty-six".