1312133231 has 4 divisors (see below), whose sum is σ = 1312206000. Its totient is φ = 1312060464.

The previous prime is 1312133213. The next prime is 1312133239. The reversal of 1312133231 is 1323312131.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1323312131 = 6577 ⋅201203.

It is a cyclic number.

It is not a de Polignac number, because 1312133231 - 2⁶ = 1312133167 is a prime.

It is a super-2 number, since 2×1312133231² = 3443387231788998722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312133239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13070 + ... + 52868.

It is an arithmetic number, because the mean of its divisors is an integer number (328051500).

Almost surely, 2^1312133231 is an apocalyptic number.

1312133231 is a deficient number, since it is larger than the sum of its proper divisors (72769).

1312133231 is an equidigital number, since it uses as much as digits as its factorization.

1312133231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72768.

The product of its digits is 324, while the sum is 20.

The square root of 1312133231 is about 36223.3796186938. The cubic root of 1312133231 is about 1094.7777899562. Note that the first 4 decimals are identical.

Adding to 1312133231 its reverse (1323312131), we get a palindrome (2635445362).

The spelling of 1312133231 in words is "one billion, three hundred twelve million, one hundred thirty-three thousand, two hundred thirty-one".