28547891 has 4 divisors (see below), whose sum is σ = 28939032. Its totient is φ = 28156752.

The previous prime is 28547839. The next prime is 28547903. The reversal of 28547891 is 19874582.

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 28547891 - 2¹⁰ = 28546867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28547801) 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, 195461 + ... + 195606.

It is an arithmetic number, because the mean of its divisors is an integer number (7234758).

Almost surely, 2^28547891 is an apocalyptic number.

28547891 is a deficient number, since it is larger than the sum of its proper divisors (391141).

28547891 is an equidigital number, since it uses as much as digits as its factorization.

28547891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391140.

The product of its digits is 161280, while the sum is 44.

The square root of 28547891 is about 5343.0226464053. The cubic root of 28547891 is about 305.6267359801.

The spelling of 28547891 in words is "twenty-eight million, five hundred forty-seven thousand, eight hundred ninety-one".