728999993 has 2 divisors, whose sum is σ = 728999994. Its totient is φ = 728999992.

The previous prime is 728999983. The next prime is 729000007. The reversal of 728999993 is 399999827.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 724040464 + 4959529 = 26908^2 + 2227^2 .

It is an emirp because it is prime and its reverse (399999827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 728999993 - 2⁸ = 728999737 is a prime.

It is not a weakly prime, because it can be changed into another prime (728999903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364499996 + 364499997.

It is an arithmetic number, because the mean of its divisors is an integer number (364499997).

Almost surely, 2^728999993 is an apocalyptic number.

It is an amenable number.

728999993 is a deficient number, since it is larger than the sum of its proper divisors (1).

728999993 is an equidigital number, since it uses as much as digits as its factorization.

728999993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19840464, while the sum is 65.

The square root of 728999993 is about 26999.9998703704. Note that the first 3 decimals coincide. The cubic root of 728999993 is about 899.9999971193. Note that the first 5 decimals are identical.

The spelling of 728999993 in words is "seven hundred twenty-eight million, nine hundred ninety-nine thousand, nine hundred ninety-three".