15616649664 has 840 divisors, whose sum is σ = 61552579968. Its totient is φ = 3879912960.

The previous prime is 15616649647. The next prime is 15616649749. The reversal of 15616649664 is 46694661651.

It is a happy number.

15616649664 is a `hidden beast` number, since 15 + 616 + 6 + 4 + 9 + 6 + 6 + 4 = 666.

It is a super-2 number, since 2×15616649664² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 15616649664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 678984757 + ... + 678984779.

Almost surely, 2^15616649664 is an apocalyptic number.

15616649664 is a gapful number since it is divisible by the number (14) 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 15616649664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30776289984).

15616649664 is an abundant number, since it is smaller than the sum of its proper divisors (45935930304).

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

15616649664 is an frugal number, since it uses more digits than its factorization.

15616649664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 46 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The spelling of 15616649664 in words is "fifteen billion, six hundred sixteen million, six hundred forty-nine thousand, six hundred sixty-four".