728678869 has 2 divisors, whose sum is σ = 728678870. Its totient is φ = 728678868.

The previous prime is 728678831. The next prime is 728678879. The reversal of 728678869 is 968876827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 658538244 + 70140625 = 25662^2 + 8375^2 .

It is an emirp because it is prime and its reverse (968876827) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-728678869 is a prime.

It is a super-2 number, since 2×728678869² = 1061945788254238322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (728678809) 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 as a sum of consecutive naturals, namely, 364339434 + 364339435.

It is an arithmetic number, because the mean of its divisors is an integer number (364339435).

Almost surely, 2^728678869 is an apocalyptic number.

It is an amenable number.

728678869 is a deficient number, since it is larger than the sum of its proper divisors (1).

728678869 is an equidigital number, since it uses as much as digits as its factorization.

728678869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16257024, while the sum is 61.

The square root of 728678869 is about 26994.0524745730. The cubic root of 728678869 is about 899.8678279155.

The spelling of 728678869 in words is "seven hundred twenty-eight million, six hundred seventy-eight thousand, eight hundred sixty-nine".