172181 has 2 divisors, whose sum is σ = 172182. Its totient is φ = 172180.

The previous prime is 172171. The next prime is 172199. The reversal of 172181 is 181271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167281 + 4900 = 409^2 + 70^2 .

It is a cyclic number.

It is not a de Polignac number, because 172181 - 2¹⁴ = 155797 is a prime.

It is a super-2 number, since 2×172181² = 59292593522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86090 + 86091.

It is an arithmetic number, because the mean of its divisors is an integer number (86091).

2¹⁷²¹⁸¹ is an apocalyptic number.

It is an amenable number.

172181 is a deficient number, since it is larger than the sum of its proper divisors (1).

172181 is an equidigital number, since it uses as much as digits as its factorization.

172181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112, while the sum is 20.

The square root of 172181 is about 414.9469845655. The cubic root of 172181 is about 55.6324784794.

It can be divided in two parts, 172 and 181, that added together give a palindrome (353).

The spelling of 172181 in words is "one hundred seventy-two thousand, one hundred eighty-one".