172161191 has 2 divisors, whose sum is σ = 172161192. Its totient is φ = 172161190.

The previous prime is 172161169. The next prime is 172161217. The reversal of 172161191 is 191161271.

172161191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 172161191 - 2⁶ = 172161127 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172161991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86080595 + 86080596.

It is an arithmetic number, because the mean of its divisors is an integer number (86080596).

Almost surely, 2^172161191 is an apocalyptic number.

172161191 is a deficient number, since it is larger than the sum of its proper divisors (1).

172161191 is an equidigital number, since it uses as much as digits as its factorization.

172161191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 29.

The square root of 172161191 is about 13121.0209587516. The cubic root of 172161191 is about 556.3034493773.

The spelling of 172161191 in words is "one hundred seventy-two million, one hundred sixty-one thousand, one hundred ninety-one".