28316993 has 4 divisors (see below), whose sum is σ = 28781268. Its totient is φ = 27852720.

The previous prime is 28316989. The next prime is 28317007. The reversal of 28316993 is 39961382.

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 1763584 + 26553409 = 1328^2 + 5153^2 .

It is a cyclic number.

It is not a de Polignac number, because 28316993 - 2² = 28316989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28316993.

It is not an unprimeable number, because it can be changed into a prime (28316903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 232046 + ... + 232167.

It is an arithmetic number, because the mean of its divisors is an integer number (7195317).

Almost surely, 2^28316993 is an apocalyptic number.

It is an amenable number.

28316993 is a deficient number, since it is larger than the sum of its proper divisors (464275).

28316993 is an equidigital number, since it uses as much as digits as its factorization.

28316993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464274.

The product of its digits is 69984, while the sum is 41.

The square root of 28316993 is about 5321.3713458093. The cubic root of 28316993 is about 304.8005253066.

The spelling of 28316993 in words is "twenty-eight million, three hundred sixteen thousand, nine hundred ninety-three".