28685543 has 4 divisors (see below), whose sum is σ = 28705248. Its totient is φ = 28665840.

The previous prime is 28685533. The next prime is 28685549. The reversal of 28685543 is 34558682.

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 28685543 - 2⁶ = 28685479 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 28685543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28685549) 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, 7478 + ... + 10643.

It is an arithmetic number, because the mean of its divisors is an integer number (7176312).

Almost surely, 2^28685543 is an apocalyptic number.

28685543 is a deficient number, since it is larger than the sum of its proper divisors (19705).

28685543 is a wasteful number, since it uses less digits than its factorization.

28685543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19704.

The product of its digits is 230400, while the sum is 41.

The square root of 28685543 is about 5355.8886284164. Note that the first 3 decimals coincide. The cubic root of 28685543 is about 306.1171714406.

The spelling of 28685543 in words is "twenty-eight million, six hundred eighty-five thousand, five hundred forty-three".