1311431331 has 32 divisors (see below), whose sum is σ = 2023676928. Its totient is φ = 739952640.

The previous prime is 1311431321. The next prime is 1311431389. The reversal of 1311431331 is 1331341131.

It is not a de Polignac number, because 1311431331 - 2¹⁷ = 1311300259 is a prime.

It is a super-2 number, since 2×1311431331² = 3439704271856863122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 1311431298 and 1311431307.

It is not an unprimeable number, because it can be changed into a prime (1311431321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 737115 + ... + 738891.

It is an arithmetic number, because the mean of its divisors is an integer number (63239904).

Almost surely, 2^1311431331 is an apocalyptic number.

1311431331 is a deficient number, since it is larger than the sum of its proper divisors (712245597).

1311431331 is a wasteful number, since it uses less digits than its factorization.

1311431331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2211.

The product of its digits is 324, while the sum is 21.

The square root of 1311431331 is about 36213.6898285717. The cubic root of 1311431331 is about 1094.5825451514.

Adding to 1311431331 its reverse (1331341131), we get a palindrome (2642772462).

The spelling of 1311431331 in words is "one billion, three hundred eleven million, four hundred thirty-one thousand, three hundred thirty-one".