728345291 has 4 divisors (see below), whose sum is σ = 731033184. Its totient is φ = 725657400.

The previous prime is 728345287. The next prime is 728345357. The reversal of 728345291 is 192543827.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 192543827 = 7 ⋅27506261.

It is a cyclic number.

It is not a de Polignac number, because 728345291 - 2² = 728345287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728345231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1343540 + ... + 1344081.

It is an arithmetic number, because the mean of its divisors is an integer number (182758296).

Almost surely, 2^728345291 is an apocalyptic number.

728345291 is a deficient number, since it is larger than the sum of its proper divisors (2687893).

728345291 is a wasteful number, since it uses less digits than its factorization.

728345291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2687892.

The product of its digits is 120960, while the sum is 41.

The square root of 728345291 is about 26987.8730358656. The cubic root of 728345291 is about 899.7304917308.

It can be divided in two parts, 72834 and 5291, that added together give a 7-th power (78125 = 5⁷).

The spelling of 728345291 in words is "seven hundred twenty-eight million, three hundred forty-five thousand, two hundred ninety-one".