28333709 has 4 divisors (see below), whose sum is σ = 28721916. Its totient is φ = 27945504.

The previous prime is 28333703. The next prime is 28333727. The reversal of 28333709 is 90733382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90733382 = 2 ⋅45366691.

It can be written as a sum of positive squares in 2 ways, for example, as 24780484 + 3553225 = 4978^2 + 1885^2 .

It is a cyclic number.

It is not a de Polignac number, because 28333709 - 2²⁰ = 27285133 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28333703) 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, 193994 + ... + 194139.

It is an arithmetic number, because the mean of its divisors is an integer number (7180479).

Almost surely, 2^28333709 is an apocalyptic number.

It is an amenable number.

28333709 is a deficient number, since it is larger than the sum of its proper divisors (388207).

28333709 is an equidigital number, since it uses as much as digits as its factorization.

28333709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388206.

The product of its (nonzero) digits is 27216, while the sum is 35.

The square root of 28333709 is about 5322.9417618456. The cubic root of 28333709 is about 304.8604898109.

The spelling of 28333709 in words is "twenty-eight million, three hundred thirty-three thousand, seven hundred nine".