313231121221 has 8 divisors (see below), whose sum is σ = 317531731160. Its totient is φ = 308930775552.

The previous prime is 313231121201. The next prime is 313231121279. The reversal of 313231121221 is 122121132313.

It can be written as a sum of positive squares in 4 ways, for example, as 24984544225 + 288246576996 = 158065^2 + 536886^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-313231121221 is a prime.

It is a super-2 number, since 2×313231121221² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 313231121192 and 313231121201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (313231121201) 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 7 ways as a sum of consecutive naturals, for example, 4175581 + ... + 4249933.

It is an arithmetic number, because the mean of its divisors is an integer number (39691466395).

Almost surely, 2^313231121221 is an apocalyptic number.

It is an amenable number.

313231121221 is a deficient number, since it is larger than the sum of its proper divisors (4300609939).

313231121221 is an equidigital number, since it uses as much as digits as its factorization.

313231121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132135.

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

Adding to 313231121221 its reverse (122121132313), we get a palindrome (435352253534).

The spelling of 313231121221 in words is "three hundred thirteen billion, two hundred thirty-one million, one hundred twenty-one thousand, two hundred twenty-one".