728178449 has 2 divisors, whose sum is σ = 728178450. Its totient is φ = 728178448.

The previous prime is 728178421. The next prime is 728178457. The reversal of 728178449 is 944871827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 546063424 + 182115025 = 23368^2 + 13495^2 .

It is an emirp because it is prime and its reverse (944871827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 728178449 - 2¹² = 728174353 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 728178397 and 728178406.

It is not a weakly prime, because it can be changed into another prime (728178749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364089224 + 364089225.

It is an arithmetic number, because the mean of its divisors is an integer number (364089225).

Almost surely, 2^728178449 is an apocalyptic number.

It is an amenable number.

728178449 is a deficient number, since it is larger than the sum of its proper divisors (1).

728178449 is an equidigital number, since it uses as much as digits as its factorization.

728178449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 903168, while the sum is 50.

The square root of 728178449 is about 26984.7818038242. The cubic root of 728178449 is about 899.6617860861.

The spelling of 728178449 in words is "seven hundred twenty-eight million, one hundred seventy-eight thousand, four hundred forty-nine".