131231312 has 10 divisors (see below), whose sum is σ = 254260698. Its totient is φ = 65615648.

The previous prime is 131231299. The next prime is 131231323. The reversal of 131231312 is 213132131.

131231312 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 94556176 + 36675136 = 9724^2 + 6056^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4100963 + ... + 4100994.

Almost surely, 2^131231312 is an apocalyptic number.

It is an amenable number.

131231312 is a deficient number, since it is larger than the sum of its proper divisors (123029386).

131231312 is an equidigital number, since it uses as much as digits as its factorization.

131231312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8201965 (or 8201959 counting only the distinct ones).

The product of its digits is 108, while the sum is 17.

The square root of 131231312 is about 11455.6235971683. The cubic root of 131231312 is about 508.1740573704.

Adding to 131231312 its reverse (213132131), we get a palindrome (344363443).

The spelling of 131231312 in words is "one hundred thirty-one million, two hundred thirty-one thousand, three hundred twelve".