31323131213 has 12 divisors (see below), whose sum is σ = 34442869020. Its totient is φ = 28464564480.

The previous prime is 31323131143. The next prime is 31323131219. The reversal of 31323131213 is 31213132313.

It can be written as a sum of positive squares in 2 ways, for example, as 19895948809 + 11427182404 = 141053^2 + 106898^2 .

It is not a de Polignac number, because 31323131213 - 2¹² = 31323127117 is a prime.

It is a super-2 number, since 2×31323131213² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31323131219) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 272783 + ... + 370211.

It is an arithmetic number, because the mean of its divisors is an integer number (2870239085).

Almost surely, 2^31323131213 is an apocalyptic number.

It is an amenable number.

31323131213 is a deficient number, since it is larger than the sum of its proper divisors (3119737807).

31323131213 is a wasteful number, since it uses less digits than its factorization.

31323131213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100108 (or 100097 counting only the distinct ones).

The product of its digits is 972, while the sum is 23.

Adding to 31323131213 its reverse (31213132313), we get a palindrome (62536263526).

The spelling of 31323131213 in words is "thirty-one billion, three hundred twenty-three million, one hundred thirty-one thousand, two hundred thirteen".