311222131021 has 4 divisors (see below), whose sum is σ = 327602243200. Its totient is φ = 294842018844.

The previous prime is 311222131013. The next prime is 311222131027. The reversal of 311222131021 is 120131222113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 311222131021 - 2³ = 311222131013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 16380112159 = 311222131021 / (3 + 1 + 1 + 2 + 2 + 2 + 1 + 3 + 1 + 0 + 2 + 1).

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 311222131021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311222131027) 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, 8190056061 + ... + 8190056098.

It is an arithmetic number, because the mean of its divisors is an integer number (81900560800).

Almost surely, 2^311222131021 is an apocalyptic number.

It is an amenable number.

311222131021 is a deficient number, since it is larger than the sum of its proper divisors (16380112179).

311222131021 is a wasteful number, since it uses less digits than its factorization.

311222131021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16380112178.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 311222131021 its reverse (120131222113), we get a palindrome (431353353134).

The spelling of 311222131021 in words is "three hundred eleven billion, two hundred twenty-two million, one hundred thirty-one thousand, twenty-one".