15661251360 has 144 divisors (see below), whose sum is σ = 56587874616. Its totient is φ = 3930660864.

The previous prime is 15661251329. The next prime is 15661251371. The reversal of 15661251360 is 6315216651.

15661251360 is a `hidden beast` number, since 1 + 5 + 6 + 612 + 5 + 1 + 36 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 14150529936 + 1510721424 = 118956^2 + 38868^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×15661251360² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 23 ways as a sum of consecutive naturals, for example, 295399 + ... + 344358.

Almost surely, 2^15661251360 is an apocalyptic number.

15661251360 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15661251360 is an abundant number, since it is smaller than the sum of its proper divisors (40926623256).

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

15661251360 is a wasteful number, since it uses less digits than its factorization.

15661251360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639795 (or 639784 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 15661251360 in words is "fifteen billion, six hundred sixty-one million, two hundred fifty-one thousand, three hundred sixty".