891728 has 10 divisors (see below), whose sum is σ = 1727754. Its totient is φ = 445856.

The previous prime is 891707. The next prime is 891743. The reversal of 891728 is 827198.

It is a happy number.

891728 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., 868624 + 23104 = 932^2 + 152^2 .

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

891728 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, 27851 + ... + 27882.

2⁸⁹¹⁷²⁸ is an apocalyptic number.

It is an amenable number.

891728 is a deficient number, since it is larger than the sum of its proper divisors (836026).

891728 is a wasteful number, since it uses less digits than its factorization.

891728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55741 (or 55735 counting only the distinct ones).

The product of its digits is 8064, while the sum is 35.

The square root of 891728 is about 944.3135072633. The cubic root of 891728 is about 96.2522302289.

The spelling of 891728 in words is "eight hundred ninety-one thousand, seven hundred twenty-eight".