172129 has 4 divisors (see below), whose sum is σ = 176176. Its totient is φ = 168084.

The previous prime is 172127. The next prime is 172147. The reversal of 172129 is 921271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 921271 = 13 ⋅70867.

It is a cyclic number.

It is not a de Polignac number, because 172129 - 2¹ = 172127 is a prime.

It is a Duffinian number.

172129 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (172127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1959 + ... + 2044.

It is an arithmetic number, because the mean of its divisors is an integer number (44044).

2¹⁷²¹²⁹ is an apocalyptic number.

It is an amenable number.

172129 is a deficient number, since it is larger than the sum of its proper divisors (4047).

172129 is an equidigital number, since it uses as much as digits as its factorization.

172129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4046.

The product of its digits is 252, while the sum is 22.

The square root of 172129 is about 414.8843212270. The cubic root of 172129 is about 55.6268774353.

The spelling of 172129 in words is "one hundred seventy-two thousand, one hundred twenty-nine".