1311031231 has 4 divisors (see below), whose sum is σ = 1326826872. Its totient is φ = 1295235592.

The previous prime is 1311031229. The next prime is 1311031243. The reversal of 1311031231 is 1321301131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1321301131 = 491 ⋅2691041.

It is a cyclic number.

It is not a de Polignac number, because 1311031231 - 2¹ = 1311031229 is a prime.

It is a super-2 number, since 2×1311031231² = 3437605777314750722, 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 (1311031201) 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, 7897696 + ... + 7897861.

It is an arithmetic number, because the mean of its divisors is an integer number (331706718).

Almost surely, 2^1311031231 is an apocalyptic number.

1311031231 is a deficient number, since it is larger than the sum of its proper divisors (15795641).

1311031231 is an equidigital number, since it uses as much as digits as its factorization.

1311031231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15795640.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 1311031231 is about 36208.1652531580. The cubic root of 1311031231 is about 1094.4712197087.

Adding to 1311031231 its reverse (1321301131), we get a palindrome (2632332362).

The spelling of 1311031231 in words is "one billion, three hundred eleven million, thirty-one thousand, two hundred thirty-one".