28807643 has 4 divisors (see below), whose sum is σ = 29801040. Its totient is φ = 27814248.

The previous prime is 28807637. The next prime is 28807657. The reversal of 28807643 is 34670882.

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

It is not a de Polignac number, because 28807643 - 2⁴ = 28807627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28807597 and 28807606.

It is not an unprimeable number, because it can be changed into a prime (28807693) 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, 496655 + ... + 496712.

It is an arithmetic number, because the mean of its divisors is an integer number (7450260).

Almost surely, 2^28807643 is an apocalyptic number.

28807643 is a deficient number, since it is larger than the sum of its proper divisors (993397).

28807643 is an equidigital number, since it uses as much as digits as its factorization.

28807643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 993396.

The product of its (nonzero) digits is 64512, while the sum is 38.

The square root of 28807643 is about 5367.2751932428. The cubic root of 28807643 is about 306.5508858508.

The spelling of 28807643 in words is "twenty-eight million, eight hundred seven thousand, six hundred forty-three".