311221321131 has 16 divisors (see below), whose sum is σ = 482016474368. Its totient is φ = 174925332000.

The previous prime is 311221321123. The next prime is 311221321219. The reversal of 311221321131 is 131123122113.

It is not a de Polignac number, because 311221321131 - 2³ = 311221321123 is a prime.

It is a super-2 number, since 2×311221321131² (a number of 24 digits) contains 22 as substring.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311221321098 and 311221321107.

It is not an unprimeable number, because it can be changed into a prime (311221321121) 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, 121474645 + ... + 121477206.

It is an arithmetic number, because the mean of its divisors is an integer number (30126029648).

Almost surely, 2^311221321131 is an apocalyptic number.

311221321131 is a deficient number, since it is larger than the sum of its proper divisors (170795153237).

311221321131 is a wasteful number, since it uses less digits than its factorization.

311221321131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242951922.

The product of its digits is 216, while the sum is 21.

Adding to 311221321131 its reverse (131123122113), we get a palindrome (442344443244).

The spelling of 311221321131 in words is "three hundred eleven billion, two hundred twenty-one million, three hundred twenty-one thousand, one hundred thirty-one".