31213313 has 4 divisors (see below), whose sum is σ = 31939248. Its totient is φ = 30487380.

The previous prime is 31213289. The next prime is 31213321. The reversal of 31213313 is 31331213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31331213 = 283 ⋅110711.

It is a cyclic number.

It is not a de Polignac number, because 31213313 - 2¹⁴ = 31196929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31213291 and 31213300.

It is not an unprimeable number, because it can be changed into a prime (31213363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 362903 + ... + 362988.

It is an arithmetic number, because the mean of its divisors is an integer number (7984812).

Almost surely, 2^31213313 is an apocalyptic number.

It is an amenable number.

31213313 is a deficient number, since it is larger than the sum of its proper divisors (725935).

31213313 is an equidigital number, since it uses as much as digits as its factorization.

31213313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725934.

The product of its digits is 162, while the sum is 17.

The square root of 31213313 is about 5586.8875950747. The cubic root of 31213313 is about 314.8569536108.

Adding to 31213313 its reverse (31331213), we get a palindrome (62544526).

The spelling of 31213313 in words is "thirty-one million, two hundred thirteen thousand, three hundred thirteen".