1231407311 has 4 divisors (see below), whose sum is σ = 1231623624. Its totient is φ = 1231191000.

The previous prime is 1231407283. The next prime is 1231407341. The reversal of 1231407311 is 1137041321.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1137041321 = 13 ⋅87464717.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231407311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231407341) 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, 99380 + ... + 111081.

It is an arithmetic number, because the mean of its divisors is an integer number (307905906).

Almost surely, 2^1231407311 is an apocalyptic number.

1231407311 is a deficient number, since it is larger than the sum of its proper divisors (216313).

1231407311 is an equidigital number, since it uses as much as digits as its factorization.

1231407311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216312.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 1231407311 is about 35091.4136363869. The cubic root of 1231407311 is about 1071.8497456740.

Adding to 1231407311 its reverse (1137041321), we get a palindrome (2368448632).

The spelling of 1231407311 in words is "one billion, two hundred thirty-one million, four hundred seven thousand, three hundred eleven".