311220021231 has 16 divisors (see below), whose sum is σ = 526933369600. Its totient is φ = 177840012024.

The previous prime is 311220021169. The next prime is 311220021239. The reversal of 311220021231 is 132120022113.

It is not a de Polignac number, because 311220021231 - 2¹⁰ = 311220020207 is a prime.

It is a super-2 number, since 2×311220021231² (a number of 24 digits) 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 (311220021239) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 823333201 + ... + 823333578.

It is an arithmetic number, because the mean of its divisors is an integer number (32933335600).

Almost surely, 2^311220021231 is an apocalyptic number.

311220021231 is a deficient number, since it is larger than the sum of its proper divisors (215713348369).

311220021231 is a wasteful number, since it uses less digits than its factorization.

311220021231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1646666795 (or 1646666789 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 311220021231 its reverse (132120022113), we get a palindrome (443340043344).

The spelling of 311220021231 in words is "three hundred eleven billion, two hundred twenty million, twenty-one thousand, two hundred thirty-one".