31213333213 has 4 divisors (see below), whose sum is σ = 31441167900. Its totient is φ = 30985498528.

The previous prime is 31213333187. The next prime is 31213333219. The reversal of 31213333213 is 31233331213.

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 9127509444 + 22085823769 = 95538^2 + 148613^2 .

It is a cyclic number.

It is not a de Polignac number, because 31213333213 - 2⁹ = 31213332701 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 (31213333219) 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, 113917138 + ... + 113917411.

It is an arithmetic number, because the mean of its divisors is an integer number (7860291975).

Almost surely, 2^31213333213 is an apocalyptic number.

It is an amenable number.

31213333213 is a deficient number, since it is larger than the sum of its proper divisors (227834687).

31213333213 is a wasteful number, since it uses less digits than its factorization.

31213333213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227834686.

The product of its digits is 2916, while the sum is 25.

Adding to 31213333213 its reverse (31233331213), we get a palindrome (62446664426).

The spelling of 31213333213 in words is "thirty-one billion, two hundred thirteen million, three hundred thirty-three thousand, two hundred thirteen".