1231123131 has 20 divisors (see below), whose sum is σ = 2101812592. Its totient is φ = 703498608.

The previous prime is 1231123081. The next prime is 1231123133. The reversal of 1231123131 is 1313211321.

It is not a de Polignac number, because 1231123131 - 2¹³ = 1231114939 is a prime.

It is a super-2 number, since 2×1231123131² = 3031328327366486322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231123133) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1085080 + ... + 1086213.

Almost surely, 2^1231123131 is an apocalyptic number.

1231123131 is a deficient number, since it is larger than the sum of its proper divisors (870689461).

1231123131 is an equidigital number, since it uses as much as digits as its factorization.

1231123131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2171312 (or 2171303 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 1231123131 is about 35087.3642640766. The cubic root of 1231123131 is about 1071.7672867149.

Adding to 1231123131 its reverse (1313211321), we get a palindrome (2544334452).

The spelling of 1231123131 in words is "one billion, two hundred thirty-one million, one hundred twenty-three thousand, one hundred thirty-one".