11565556665 has 32 divisors (see below), whose sum is σ = 20007824256. Its totient is φ = 5671104000.

The previous prime is 11565556657. The next prime is 11565556679. The reversal of 11565556665 is 56665556511.

It is not a de Polignac number, because 11565556665 - 2³ = 11565556657 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69204 + ... + 167093.

It is an arithmetic number, because the mean of its divisors is an integer number (625244508).

Almost surely, 2^11565556665 is an apocalyptic number.

11565556665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11565556665 is a deficient number, since it is larger than the sum of its proper divisors (8442267591).

11565556665 is a wasteful number, since it uses less digits than its factorization.

11565556665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236569.

The product of its digits is 4050000, while the sum is 51.

The spelling of 11565556665 in words is "eleven billion, five hundred sixty-five million, five hundred fifty-six thousand, six hundred sixty-five".