28709807 has 4 divisors (see below), whose sum is σ = 32811216. Its totient is φ = 24608400.

The previous prime is 28709801. The next prime is 28709851. The reversal of 28709807 is 70890782.

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 28709807 - 2¹² = 28705711 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 (28709801) 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, 2050694 + ... + 2050707.

It is an arithmetic number, because the mean of its divisors is an integer number (8202804).

Almost surely, 2^28709807 is an apocalyptic number.

28709807 is a deficient number, since it is larger than the sum of its proper divisors (4101409).

28709807 is an equidigital number, since it uses as much as digits as its factorization.

28709807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4101408.

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 28709807 is about 5358.1533199415. The cubic root of 28709807 is about 306.2034580390.

The spelling of 28709807 in words is "twenty-eight million, seven hundred nine thousand, eight hundred seven".