172865 has 16 divisors (see below), whose sum is σ = 259200. Its totient is φ = 107520.

The previous prime is 172859. The next prime is 172867. The reversal of 172865 is 568271.

172865 = 15² + 16² + ... + 80².

It is not a de Polignac number, because 172865 - 2⁴ = 172849 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (172867) 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 in 15 ways as a sum of consecutive naturals, for example, 161 + ... + 609.

It is an arithmetic number, because the mean of its divisors is an integer number (16200).

2¹⁷²⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

172865 is a deficient number, since it is larger than the sum of its proper divisors (86335).

172865 is a wasteful number, since it uses less digits than its factorization.

172865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472.

The product of its digits is 3360, while the sum is 29.

The square root of 172865 is about 415.7703693146. The cubic root of 172865 is about 55.7060489999.

It can be divided in two parts, 17 and 2865, that added together give a palindrome (2882).

The spelling of 172865 in words is "one hundred seventy-two thousand, eight hundred sixty-five".