728340538 has 4 divisors (see below), whose sum is σ = 1092510810. Its totient is φ = 364170268.

The previous prime is 728340533. The next prime is 728340559. The reversal of 728340538 is 835043827.

728340538 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 835043827 = 83 ⋅10060769.

It can be written as a sum of positive squares in only one way, i.e., 621155929 + 107184609 = 24923^2 + 10353^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 728340538.

It is not an unprimeable number, because it can be changed into a prime (728340533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 182085133 + ... + 182085136.

Almost surely, 2^728340538 is an apocalyptic number.

728340538 is a deficient number, since it is larger than the sum of its proper divisors (364170272).

728340538 is a wasteful number, since it uses less digits than its factorization.

728340538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364170271.

The product of its (nonzero) digits is 161280, while the sum is 40.

The square root of 728340538 is about 26987.7849776524. The cubic root of 728340538 is about 899.7285345875.

The spelling of 728340538 in words is "seven hundred twenty-eight million, three hundred forty thousand, five hundred thirty-eight".