15566697137664 has 140 divisors (see below), whose sum is σ = 46633154332116. Its totient is φ = 5188898921472.

The previous prime is 15566697137647. The next prime is 15566697137681. The reversal of 15566697137664 is 46673179666551.

It is an interprime number because it is at equal distance from previous prime (15566697137647) and next prime (15566697137681).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 15566697137592 and 15566697137601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 20479774 + ... + 21226269.

Almost surely, 2^{15566697137664} is an apocalyptic number.

It is an amenable number.

15566697137664 is an abundant number, since it is smaller than the sum of its proper divisors (31066457194452).

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

15566697137664 is an frugal number, since it uses more digits than its factorization.

15566697137664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41706079 (or 41706048 counting only the distinct ones).

The product of its digits is 1028764800, while the sum is 72.

The spelling of 15566697137664 in words is "fifteen trillion, five hundred sixty-six billion, six hundred ninety-seven million, one hundred thirty-seven thousand, six hundred sixty-four".