16699138858565 has 4 divisors (see below), whose sum is σ = 20038966630284. Its totient is φ = 13359311086848.

The previous prime is 16699138858559. The next prime is 16699138858573. The reversal of 16699138858565 is 56585883199661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8268977589889 + 8430161268676 = 2875583^2 + 2903474^2 .

It is a cyclic number.

It is not a de Polignac number, because 16699138858565 - 2²⁴ = 16699122081349 is a prime.

It is a super-2 number, since 2×16699138858565² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16699138858565.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1669913885852 + ... + 1669913885861.

It is an arithmetic number, because the mean of its divisors is an integer number (5009741657571).

Almost surely, 2^{16699138858565} is an apocalyptic number.

It is an amenable number.

16699138858565 is a deficient number, since it is larger than the sum of its proper divisors (3339827771719).

16699138858565 is an equidigital number, since it uses as much as digits as its factorization.

16699138858565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3339827771718.

The product of its digits is 3359232000, while the sum is 80.

The spelling of 16699138858565 in words is "sixteen trillion, six hundred ninety-nine billion, one hundred thirty-eight million, eight hundred fifty-eight thousand, five hundred sixty-five".