15691386816 has 504 divisors, whose sum is σ = 57028842000. Its totient is φ = 4096770048.

The previous prime is 15691386811. The next prime is 15691386847. The reversal of 15691386816 is 61868319651.

15691386816 is a `hidden beast` number, since 1 + 569 + 1 + 3 + 8 + 68 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15691386811) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 15550920 + ... + 15551928.

Almost surely, 2^15691386816 is an apocalyptic number.

15691386816 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 15691386816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28514421000).

15691386816 is an abundant number, since it is smaller than the sum of its proper divisors (41337455184).

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

15691386816 is a wasteful number, since it uses less digits than its factorization.

15691386816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1089 (or 1069 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 15691386816 in words is "fifteen billion, six hundred ninety-one million, three hundred eighty-six thousand, eight hundred sixteen".