331213213 has 2 divisors, whose sum is σ = 331213214. Its totient is φ = 331213212.

The previous prime is 331213189. The next prime is 331213217. The reversal of 331213213 is 312312133.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 233539524 + 97673689 = 15282^2 + 9883^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-331213213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (331213217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165606606 + 165606607.

It is an arithmetic number, because the mean of its divisors is an integer number (165606607).

Almost surely, 2^331213213 is an apocalyptic number.

It is an amenable number.

331213213 is a deficient number, since it is larger than the sum of its proper divisors (1).

331213213 is an equidigital number, since it uses as much as digits as its factorization.

331213213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 324, while the sum is 19.

The square root of 331213213 is about 18199.2640785280. The cubic root of 331213213 is about 691.8881373583. Note that the first 3 decimals are identical.

Adding to 331213213 its reverse (312312133), we get a palindrome (643525346).

The spelling of 331213213 in words is "three hundred thirty-one million, two hundred thirteen thousand, two hundred thirteen".