311131031221 has 4 divisors (see below), whose sum is σ = 321859687500. Its totient is φ = 300402374944.

The previous prime is 311131031219. The next prime is 311131031333. The reversal of 311131031221 is 122130131113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122130131113 = 14249 ⋅8571137.

It can be written as a sum of positive squares in 2 ways, for example, as 265008744100 + 46122287121 = 514790^2 + 214761^2 .

It is a cyclic number.

It is not a de Polignac number, because 311131031221 - 2¹ = 311131031219 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 (311131038221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5364328096 + ... + 5364328153.

It is an arithmetic number, because the mean of its divisors is an integer number (80464921875).

Almost surely, 2^311131031221 is an apocalyptic number.

It is an amenable number.

311131031221 is a deficient number, since it is larger than the sum of its proper divisors (10728656279).

311131031221 is a wasteful number, since it uses less digits than its factorization.

311131031221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10728656278.

The product of its (nonzero) digits is 108, while the sum is 19.

Adding to 311131031221 its reverse (122130131113), we get a palindrome (433261162334).

The spelling of 311131031221 in words is "three hundred eleven billion, one hundred thirty-one million, thirty-one thousand, two hundred twenty-one".