231212213 has 2 divisors, whose sum is σ = 231212214. Its totient is φ = 231212212.

The previous prime is 231212171. The next prime is 231212231. The reversal of 231212213 is 312212132.

Together with next prime (231212231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205578244 + 25633969 = 14338^2 + 5063^2 .

It is a cyclic number.

It is not a de Polignac number, because 231212213 - 2⁸ = 231211957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231212191 and 231212200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231212713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115606106 + 115606107.

It is an arithmetic number, because the mean of its divisors is an integer number (115606107).

Almost surely, 2^231212213 is an apocalyptic number.

It is an amenable number.

231212213 is a deficient number, since it is larger than the sum of its proper divisors (1).

231212213 is an equidigital number, since it uses as much as digits as its factorization.

231212213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 17.

The square root of 231212213 is about 15205.6638460805. The cubic root of 231212213 is about 613.7670789434.

Adding to 231212213 its reverse (312212132), we get a palindrome (543424345).

The spelling of 231212213 in words is "two hundred thirty-one million, two hundred twelve thousand, two hundred thirteen".