172117217 has 2 divisors, whose sum is σ = 172117218. Its totient is φ = 172117216.

The previous prime is 172117159. The next prime is 172117237. The reversal of 172117217 is 712711271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166900561 + 5216656 = 12919^2 + 2284^2 .

It is a cyclic number.

It is not a de Polignac number, because 172117217 - 2¹⁶ = 172051681 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 172117217.

It is not a weakly prime, because it can be changed into another prime (172117237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86058608 + 86058609.

It is an arithmetic number, because the mean of its divisors is an integer number (86058609).

Almost surely, 2^172117217 is an apocalyptic number.

It is an amenable number.

172117217 is a deficient number, since it is larger than the sum of its proper divisors (1).

172117217 is an equidigital number, since it uses as much as digits as its factorization.

172117217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1372, while the sum is 29.

The square root of 172117217 is about 13119.3451437181. The cubic root of 172117217 is about 556.2560810344.

Adding to 172117217 its reverse (712711271), we get a palindrome (884828488).

The spelling of 172117217 in words is "one hundred seventy-two million, one hundred seventeen thousand, two hundred seventeen".