491728 has 20 divisors (see below), whose sum is σ = 968068. Its totient is φ = 241920.

The previous prime is 491719. The next prime is 491731. The reversal of 491728 is 827194.

It can be written as a sum of positive squares in 2 ways, for example, as 97344 + 394384 = 312^2 + 628^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 491728.

It is a congruent number.

It is an unprimeable number.

491728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 958 + ... + 1378.

2⁴⁹¹⁷²⁸ is an apocalyptic number.

It is an amenable number.

491728 is a deficient number, since it is larger than the sum of its proper divisors (476340).

491728 is a wasteful number, since it uses less digits than its factorization.

491728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502 (or 496 counting only the distinct ones).

The product of its digits is 4032, while the sum is 31.

The square root of 491728 is about 701.2331994422. The cubic root of 491728 is about 78.9299170159.

The spelling of 491728 in words is "four hundred ninety-one thousand, seven hundred twenty-eight".