231445217 has 2 divisors, whose sum is σ = 231445218. Its totient is φ = 231445216.

The previous prime is 231445169. The next prime is 231445241. The reversal of 231445217 is 712544132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201753616 + 29691601 = 14204^2 + 5449^2 .

It is a cyclic number.

It is not a de Polignac number, because 231445217 - 2⁶ = 231445153 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 231445217.

It is not a weakly prime, because it can be changed into another prime (231445817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115722608 + 115722609.

It is an arithmetic number, because the mean of its divisors is an integer number (115722609).

Almost surely, 2^231445217 is an apocalyptic number.

It is an amenable number.

231445217 is a deficient number, since it is larger than the sum of its proper divisors (1).

231445217 is an equidigital number, since it uses as much as digits as its factorization.

231445217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 29.

The square root of 231445217 is about 15213.3236671018. The cubic root of 231445217 is about 613.9731842208.

Adding to 231445217 its reverse (712544132), we get a palindrome (943989349).

The spelling of 231445217 in words is "two hundred thirty-one million, four hundred forty-five thousand, two hundred seventeen".