28009799 has 4 divisors (see below), whose sum is σ = 28109760. Its totient is φ = 27909840.

The previous prime is 28009789. The next prime is 28009801. The reversal of 28009799 is 99790082.

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

It is a cyclic number.

It is not a de Polignac number, because 28009799 - 2⁸ = 28009543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28009739) 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, 49559 + ... + 50120.

It is an arithmetic number, because the mean of its divisors is an integer number (7027440).

Almost surely, 2^28009799 is an apocalyptic number.

28009799 is a deficient number, since it is larger than the sum of its proper divisors (99961).

28009799 is an equidigital number, since it uses as much as digits as its factorization.

28009799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99960.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 28009799 is about 5292.4284596015. The cubic root of 28009799 is about 303.6943163124.

The spelling of 28009799 in words is "twenty-eight million, nine thousand, seven hundred ninety-nine".