172331213 has 2 divisors, whose sum is σ = 172331214. Its totient is φ = 172331212.

The previous prime is 172331209. The next prime is 172331221. The reversal of 172331213 is 312133271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105124009 + 67207204 = 10253^2 + 8198^2 .

It is a cyclic number.

It is not a de Polignac number, because 172331213 - 2² = 172331209 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172331113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86165606 + 86165607.

It is an arithmetic number, because the mean of its divisors is an integer number (86165607).

Almost surely, 2^172331213 is an apocalyptic number.

It is an amenable number.

172331213 is a deficient number, since it is larger than the sum of its proper divisors (1).

172331213 is an equidigital number, since it uses as much as digits as its factorization.

172331213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 23.

The square root of 172331213 is about 13127.4983526946. The cubic root of 172331213 is about 556.4865194900.

Adding to 172331213 its reverse (312133271), we get a palindrome (484464484).

The spelling of 172331213 in words is "one hundred seventy-two million, three hundred thirty-one thousand, two hundred thirteen".