31133312213 has 4 divisors (see below), whose sum is σ = 31133667468. Its totient is φ = 31132956960.

The previous prime is 31133312137. The next prime is 31133312251. The reversal of 31133312213 is 31221333113.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 31221333113 = 61 ⋅511825133.

It can be written as a sum of positive squares in 2 ways, for example, as 27889668004 + 3243644209 = 167002^2 + 56953^2 .

It is a cyclic number.

It is not a de Polignac number, because 31133312213 - 2¹⁴ = 31133295829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31133362213) 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, 58145 + ... + 256217.

It is an arithmetic number, because the mean of its divisors is an integer number (7783416867).

Almost surely, 2^31133312213 is an apocalyptic number.

It is an amenable number.

31133312213 is a deficient number, since it is larger than the sum of its proper divisors (355255).

31133312213 is a wasteful number, since it uses less digits than its factorization.

31133312213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355254.

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

Adding to 31133312213 its reverse (31221333113), we get a palindrome (62354645326).

The spelling of 31133312213 in words is "thirty-one billion, one hundred thirty-three million, three hundred twelve thousand, two hundred thirteen".