1231513331 has 2 divisors, whose sum is σ = 1231513332. Its totient is φ = 1231513330.

The previous prime is 1231513279. The next prime is 1231513369. The reversal of 1231513331 is 1333151321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1231513331 - 2³⁰ = 157771507 is a prime.

It is a super-2 number, since 2×1231513331² = 3033250168861431122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1231513297 and 1231513306.

It is not a weakly prime, because it can be changed into another prime (1231518331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615756665 + 615756666.

It is an arithmetic number, because the mean of its divisors is an integer number (615756666).

Almost surely, 2^1231513331 is an apocalyptic number.

1231513331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231513331 is an equidigital number, since it uses as much as digits as its factorization.

1231513331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 810, while the sum is 23.

The square root of 1231513331 is about 35092.9242298216. The cubic root of 1231513331 is about 1071.8805056692.

Adding to 1231513331 its reverse (1333151321), we get a palindrome (2564664652).

The spelling of 1231513331 in words is "one billion, two hundred thirty-one million, five hundred thirteen thousand, three hundred thirty-one".