311331213 has 12 divisors (see below), whose sum is σ = 450126300. Its totient is φ = 207357696.

The previous prime is 311331191. The next prime is 311331221. The reversal of 311331213 is 312133113.

It is a happy number.

311331213 is a `hidden beast` number, since 311 + 331 + 21 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 293539689 + 17791524 = 17133^2 + 4218^2 .

It is not a de Polignac number, because 311331213 - 2¹⁰ = 311330189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311331263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5988 + ... + 25661.

It is an arithmetic number, because the mean of its divisors is an integer number (37510525).

Almost surely, 2^311331213 is an apocalyptic number.

It is an amenable number.

311331213 is a deficient number, since it is larger than the sum of its proper divisors (138795087).

311331213 is a wasteful number, since it uses less digits than its factorization.

311331213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32748 (or 32745 counting only the distinct ones).

The product of its digits is 162, while the sum is 18.

The square root of 311331213 is about 17644.5802727070. The cubic root of 311331213 is about 677.7573269402.

Adding to 311331213 its reverse (312133113), we get a palindrome (623464326).

The spelling of 311331213 in words is "three hundred eleven million, three hundred thirty-one thousand, two hundred thirteen".