311213221321 has 4 divisors (see below), whose sum is σ = 311506543044. Its totient is φ = 310919899600.

The previous prime is 311213221273. The next prime is 311213221357. The reversal of 311213221321 is 123122312113.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 163265291721 + 147947929600 = 404061^2 + 384640^2 .

It is a cyclic number.

It is not a de Polignac number, because 311213221321 - 2¹⁷ = 311213090249 is a prime.

It is a super-3 number, since 3×311213221321³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 311213221292 and 311213221301.

It is not an unprimeable number, because it can be changed into a prime (311213221391) 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, 146659270 + ... + 146661391.

It is an arithmetic number, because the mean of its divisors is an integer number (77876635761).

Almost surely, 2^311213221321 is an apocalyptic number.

It is an amenable number.

311213221321 is a deficient number, since it is larger than the sum of its proper divisors (293321723).

311213221321 is a wasteful number, since it uses less digits than its factorization.

311213221321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293321722.

The product of its digits is 432, while the sum is 22.

Adding to 311213221321 its reverse (123122312113), we get a palindrome (434335533434).

The spelling of 311213221321 in words is "three hundred eleven billion, two hundred thirteen million, two hundred twenty-one thousand, three hundred twenty-one".