11666555123 has 4 divisors (see below), whose sum is σ = 12280584360. Its totient is φ = 11052525888.

The previous prime is 11666555113. The next prime is 11666555143. The reversal of 11666555123 is 32155566611.

11666555123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32155566611 = 7 ⋅4593652373.

It is a cyclic number.

It is not a de Polignac number, because 11666555123 - 2⁶ = 11666555059 is a prime.

It is a super-2 number, since 2×11666555123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11666555113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 307014590 + ... + 307014627.

It is an arithmetic number, because the mean of its divisors is an integer number (3070146090).

Almost surely, 2^11666555123 is an apocalyptic number.

11666555123 is a deficient number, since it is larger than the sum of its proper divisors (614029237).

11666555123 is an equidigital number, since it uses as much as digits as its factorization.

11666555123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614029236.

The product of its digits is 162000, while the sum is 41.

The spelling of 11666555123 in words is "eleven billion, six hundred sixty-six million, five hundred fifty-five thousand, one hundred twenty-three".