13599765665 has 4 divisors (see below), whose sum is σ = 16319718804. Its totient is φ = 10879812528.

The previous prime is 13599765653. The next prime is 13599765721. The reversal of 13599765665 is 56656799531.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56656799531 = 56239 ⋅1007429.

It can be written as a sum of positive squares in 2 ways, for example, as 8134416481 + 5465349184 = 90191^2 + 73928^2 .

It is a cyclic number.

It is not a de Polignac number, because 13599765665 - 2⁴ = 13599765649 is a prime.

It is a super-2 number, since 2×13599765665² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13599765598 and 13599765607.

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, 1359976562 + ... + 1359976571.

It is an arithmetic number, because the mean of its divisors is an integer number (4079929701).

Almost surely, 2^13599765665 is an apocalyptic number.

It is an amenable number.

13599765665 is a deficient number, since it is larger than the sum of its proper divisors (2719953139).

13599765665 is an equidigital number, since it uses as much as digits as its factorization.

13599765665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2719953138.

The product of its digits is 45927000, while the sum is 62.

The spelling of 13599765665 in words is "thirteen billion, five hundred ninety-nine million, seven hundred sixty-five thousand, six hundred sixty-five".