1231311311 has 4 divisors (see below), whose sum is σ = 1257509472. Its totient is φ = 1205113152.

The previous prime is 1231311299. The next prime is 1231311329. The reversal of 1231311311 is 1131131321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1131131321 = 137 ⋅8256433.

It is a cyclic number.

It is not a de Polignac number, because 1231311311 - 2⁶ = 1231311247 is a prime.

It is a super-2 number, since 2×1231311311² = 3032255089193077442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231311311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231311611) 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, 13099010 + ... + 13099103.

It is an arithmetic number, because the mean of its divisors is an integer number (314377368).

Almost surely, 2^1231311311 is an apocalyptic number.

1231311311 is a deficient number, since it is larger than the sum of its proper divisors (26198161).

1231311311 is an equidigital number, since it uses as much as digits as its factorization.

1231311311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26198160.

The product of its digits is 54, while the sum is 17.

The square root of 1231311311 is about 35090.0457537462. The cubic root of 1231311311 is about 1071.8218912972.

Adding to 1231311311 its reverse (1131131321), we get a palindrome (2362442632).

The spelling of 1231311311 in words is "one billion, two hundred thirty-one million, three hundred eleven thousand, three hundred eleven".