728191 has 2 divisors, whose sum is σ = 728192. Its totient is φ = 728190.

The previous prime is 728173. The next prime is 728207. The reversal of 728191 is 191827.

It is a strong prime.

It is an emirp because it is prime and its reverse (191827) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-728191 is a prime.

It is a Chen prime.

728191 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (728131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364095 + 364096.

It is an arithmetic number, because the mean of its divisors is an integer number (364096).

2⁷²⁸¹⁹¹ is an apocalyptic number.

728191 is a deficient number, since it is larger than the sum of its proper divisors (1).

728191 is an equidigital number, since it uses as much as digits as its factorization.

728191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 28.

The square root of 728191 is about 853.3410806940. The cubic root of 728191 is about 89.9666954961.

It can be divided in two parts, 728 and 191, that added together give a palindrome (919).

The spelling of 728191 in words is "seven hundred twenty-eight thousand, one hundred ninety-one".