13566915685 has 4 divisors (see below), whose sum is σ = 16280298828. Its totient is φ = 10853532544.

The previous prime is 13566915679. The next prime is 13566915721. The reversal of 13566915685 is 58651966531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58651966531 = 2927 ⋅20038253.

It can be written as a sum of positive squares in 2 ways, for example, as 10647350596 + 2919565089 = 103186^2 + 54033^2 .

It is a cyclic number.

It is not a de Polignac number, because 13566915685 - 2¹³ = 13566907493 is a prime.

It is a super-2 number, since 2×13566915685² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

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, 1356691564 + ... + 1356691573.

It is an arithmetic number, because the mean of its divisors is an integer number (4070074707).

Almost surely, 2^13566915685 is an apocalyptic number.

It is an amenable number.

13566915685 is a deficient number, since it is larger than the sum of its proper divisors (2713383143).

13566915685 is an equidigital number, since it uses as much as digits as its factorization.

13566915685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2713383142.

The product of its digits is 5832000, while the sum is 55.

The spelling of 13566915685 in words is "thirteen billion, five hundred sixty-six million, nine hundred fifteen thousand, six hundred eighty-five".