15388779149856 has 360 divisors, whose sum is σ = 52656997654800. Its totient is φ = 4395961559808.

The previous prime is 15388779149837. The next prime is 15388779149893. The reversal of 15388779149856 is 65894197788351.

It is a happy number.

15388779149856 is a `hidden beast` number, since 1 + 5 + 3 + 8 + 8 + 7 + 79 + 1 + 498 + 56 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1046919595 + ... + 1046934293.

It is an arithmetic number, because the mean of its divisors is an integer number (146269437930).

Almost surely, 2^{15388779149856} is an apocalyptic number.

15388779149856 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 15388779149856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26328498827400).

15388779149856 is an abundant number, since it is smaller than the sum of its proper divisors (37268218504944).

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

15388779149856 is a wasteful number, since it uses less digits than its factorization.

15388779149856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22978 (or 22954 counting only the distinct ones).

The product of its digits is 3657830400, while the sum is 81.

The spelling of 15388779149856 in words is "fifteen trillion, three hundred eighty-eight billion, seven hundred seventy-nine million, one hundred forty-nine thousand, eight hundred fifty-six".