11666623165 has 4 divisors (see below), whose sum is σ = 13999947804. Its totient is φ = 9333298528.

The previous prime is 11666623147. The next prime is 11666623169. The reversal of 11666623165 is 56132666611.

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 8564021764 + 3102601401 = 92542^2 + 55701^2 .

It is a cyclic number.

It is not a de Polignac number, because 11666623165 - 2⁷ = 11666623037 is a prime.

It is a super-2 number, since 2×11666623165² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11666623169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1166662312 + ... + 1166662321.

It is an arithmetic number, because the mean of its divisors is an integer number (3499986951).

Almost surely, 2^11666623165 is an apocalyptic number.

It is an amenable number.

11666623165 is a deficient number, since it is larger than the sum of its proper divisors (2333324639).

11666623165 is an equidigital number, since it uses as much as digits as its factorization.

11666623165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333324638.

The product of its digits is 233280, while the sum is 43.

The spelling of 11666623165 in words is "eleven billion, six hundred sixty-six million, six hundred twenty-three thousand, one hundred sixty-five".