31122331213 has 4 divisors (see below), whose sum is σ = 31320562780. Its totient is φ = 30924099648.

The previous prime is 31122331181. The next prime is 31122331231. The reversal of 31122331213 is 31213322113.

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 9852150564 + 21270180649 = 99258^2 + 145843^2 .

It is a cyclic number.

It is not a de Polignac number, because 31122331213 - 2⁵ = 31122331181 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 (31122338213) 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, 99115548 + ... + 99115861.

It is an arithmetic number, because the mean of its divisors is an integer number (7830140695).

Almost surely, 2^31122331213 is an apocalyptic number.

It is an amenable number.

31122331213 is a deficient number, since it is larger than the sum of its proper divisors (198231567).

31122331213 is a wasteful number, since it uses less digits than its factorization.

31122331213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198231566.

The product of its digits is 648, while the sum is 22.

Adding to 31122331213 its reverse (31213322113), we get a palindrome (62335653326).

The spelling of 31122331213 in words is "thirty-one billion, one hundred twenty-two million, three hundred thirty-one thousand, two hundred thirteen".