216320317 has 2 divisors, whose sum is σ = 216320318. Its totient is φ = 216320316.

The previous prime is 216320311. The next prime is 216320341. The reversal of 216320317 is 713023612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209062681 + 7257636 = 14459^2 + 2694^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216320317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216320291 and 216320300.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216320311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108160158 + 108160159.

It is an arithmetic number, because the mean of its divisors is an integer number (108160159).

Almost surely, 2^216320317 is an apocalyptic number.

It is an amenable number.

216320317 is a deficient number, since it is larger than the sum of its proper divisors (1).

216320317 is an equidigital number, since it uses as much as digits as its factorization.

216320317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 216320317 is about 14707.8318252555. The cubic root of 216320317 is about 600.2964433263.

Adding to 216320317 its reverse (713023612), we get a palindrome (929343929).

The spelling of 216320317 in words is "two hundred sixteen million, three hundred twenty thousand, three hundred seventeen".