172728 has 24 divisors (see below), whose sum is σ = 468000. Its totient is φ = 57552.

The previous prime is 172721. The next prime is 172741. The reversal of 172728 is 827271.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172721) by changing a digit.

172728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1128 + ... + 1271.

It is an arithmetic number, because the mean of its divisors is an integer number (19500).

2¹⁷²⁷²⁸ is an apocalyptic number.

172728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

172728 is an abundant number, since it is smaller than the sum of its proper divisors (295272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

172728 is a wasteful number, since it uses less digits than its factorization.

172728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2411 (or 2404 counting only the distinct ones).

The product of its digits is 1568, while the sum is 27.

The square root of 172728 is about 415.6055822532. The cubic root of 172728 is about 55.6913289473.

Adding to 172728 its reverse (827271), we get a palindrome (999999).

It can be divided in two parts, 172 and 728, that added together give a square (900 = 30²).

The spelling of 172728 in words is "one hundred seventy-two thousand, seven hundred twenty-eight".