28297793 has 4 divisors (see below), whose sum is σ = 28685508. Its totient is φ = 27910080.

The previous prime is 28297777. The next prime is 28297861. The reversal of 28297793 is 39779282.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8334769 + 19963024 = 2887^2 + 4468^2 .

It is a cyclic number.

It is not a de Polignac number, because 28297793 - 2⁴ = 28297777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28297723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 193748 + ... + 193893.

It is an arithmetic number, because the mean of its divisors is an integer number (7171377).

Almost surely, 2^28297793 is an apocalyptic number.

It is an amenable number.

28297793 is a deficient number, since it is larger than the sum of its proper divisors (387715).

28297793 is an equidigital number, since it uses as much as digits as its factorization.

28297793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387714.

The product of its digits is 381024, while the sum is 47.

The square root of 28297793 is about 5319.5669936565. The cubic root of 28297793 is about 304.7316209418.

The spelling of 28297793 in words is "twenty-eight million, two hundred ninety-seven thousand, seven hundred ninety-three".