172217231 has 2 divisors, whose sum is σ = 172217232. Its totient is φ = 172217230.

The previous prime is 172217219. The next prime is 172217233. The reversal of 172217231 is 132712271.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 172217231 - 2²² = 168022927 is a prime.

It is a super-2 number, since 2×172217231² = 59317549306614722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 172217233, it forms a pair of twin primes.

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 172217231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172217233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86108615 + 86108616.

It is an arithmetic number, because the mean of its divisors is an integer number (86108616).

Almost surely, 2^172217231 is an apocalyptic number.

172217231 is a deficient number, since it is larger than the sum of its proper divisors (1).

172217231 is an equidigital number, since it uses as much as digits as its factorization.

172217231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1176, while the sum is 26.

The square root of 172217231 is about 13123.1562895517. The cubic root of 172217231 is about 556.3638034039.

The spelling of 172217231 in words is "one hundred seventy-two million, two hundred seventeen thousand, two hundred thirty-one".