123111312131 has 12 divisors (see below), whose sum is σ = 125374600632. Its totient is φ = 120888145344.

The previous prime is 123111312073. The next prime is 123111312167. The reversal of 123111312131 is 131213111321.

It is a de Polignac number, because none of the positive numbers 2^k-123111312131 is a prime.

It is a super-2 number, since 2×123111312131² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123111312631) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3137771 + ... + 3176763.

It is an arithmetic number, because the mean of its divisors is an integer number (10447883386).

Almost surely, 2^123111312131 is an apocalyptic number.

123111312131 is a deficient number, since it is larger than the sum of its proper divisors (2263288501).

123111312131 is an frugal number, since it uses more digits than its factorization.

123111312131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40018 (or 39959 counting only the distinct ones).

The product of its digits is 108, while the sum is 20.

Adding to 123111312131 its reverse (131213111321), we get a palindrome (254324423452).

The spelling of 123111312131 in words is "one hundred twenty-three billion, one hundred eleven million, three hundred twelve thousand, one hundred thirty-one".