123665111131 has 4 divisors (see below), whose sum is σ = 126541043992. Its totient is φ = 120789178272.

The previous prime is 123665111113. The next prime is 123665111153. The reversal of 123665111131 is 131111566321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 123665111131 - 2²⁷ = 123530893403 is a prime.

It is a super-2 number, since 2×123665111131² (a number of 23 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 = 123665111093 and 123665111102.

It is not an unprimeable number, because it can be changed into a prime (123665151131) 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, 1437966366 + ... + 1437966451.

It is an arithmetic number, because the mean of its divisors is an integer number (31635260998).

Almost surely, 2^123665111131 is an apocalyptic number.

123665111131 is a deficient number, since it is larger than the sum of its proper divisors (2875932861).

123665111131 is an equidigital number, since it uses as much as digits as its factorization.

123665111131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2875932860.

The product of its digits is 3240, while the sum is 31.

Adding to 123665111131 its reverse (131111566321), we get a palindrome (254776677452).

The spelling of 123665111131 in words is "one hundred twenty-three billion, six hundred sixty-five million, one hundred eleven thousand, one hundred thirty-one".