170728 has 8 divisors (see below), whose sum is σ = 320130. Its totient is φ = 85360.

The previous prime is 170711. The next prime is 170741. The reversal of 170728 is 827071.

It is a happy number.

170728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 91204 + 79524 = 302^2 + 282^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 15.

It is an unprimeable number.

170728 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 as a sum of consecutive naturals, namely, 10663 + ... + 10678.

2¹⁷⁰⁷²⁸ is an apocalyptic number.

It is an amenable number.

170728 is a deficient number, since it is larger than the sum of its proper divisors (149402).

170728 is a wasteful number, since it uses less digits than its factorization.

170728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21347 (or 21343 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 25.

The square root of 170728 is about 413.1924491082. The cubic root of 170728 is about 55.4755458644.

Adding to 170728 its reverse (827071), we get a palindrome (997799).

It can be divided in two parts, 170 and 728, that added together give a palindrome (898).

The spelling of 170728 in words is "one hundred seventy thousand, seven hundred twenty-eight".