15661623744 has 336 divisors, whose sum is σ = 49988370432. Its totient is φ = 4657637376.

The previous prime is 15661623737. The next prime is 15661623751. The reversal of 15661623744 is 44732616651.

15661623744 is a `hidden beast` number, since 1 + 5 + 6 + 616 + 23 + 7 + 4 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (15661623737) and next prime (15661623751).

It is a self number, because there is not a number n which added to its sum of digits gives 15661623744.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 40891777 + ... + 40892159.

It is an arithmetic number, because the mean of its divisors is an integer number (148774912).

Almost surely, 2^15661623744 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15661623744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24994185216).

15661623744 is an abundant number, since it is smaller than the sum of its proper divisors (34326746688).

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

15661623744 is a wasteful number, since it uses less digits than its factorization.

15661623744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584 (or 571 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The spelling of 15661623744 in words is "fifteen billion, six hundred sixty-one million, six hundred twenty-three thousand, seven hundred forty-four".