13599765666 has 12 divisors (see below), whose sum is σ = 29466158982. Its totient is φ = 4533255216.

The previous prime is 13599765653. The next prime is 13599765721. The reversal of 13599765666 is 66656799531.

It can be written as a sum of positive squares in only one way, i.e., 12917459025 + 682306641 = 113655^2 + 26121^2 .

It is a super-2 number, since 2×13599765666² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 377771251 + ... + 377771286.

Almost surely, 2^13599765666 is an apocalyptic number.

13599765666 is an abundant number, since it is smaller than the sum of its proper divisors (15866393316).

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

13599765666 is a wasteful number, since it uses less digits than its factorization.

13599765666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755542545 (or 755542542 counting only the distinct ones).

The product of its digits is 55112400, while the sum is 63.

The spelling of 13599765666 in words is "thirteen billion, five hundred ninety-nine million, seven hundred sixty-five thousand, six hundred sixty-six".