28384891 has 4 divisors (see below), whose sum is σ = 28413000. Its totient is φ = 28356784.

The previous prime is 28384861. The next prime is 28384897. The reversal of 28384891 is 19848382.

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 28384891 - 2⁹ = 28384379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28384897) 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, 12481 + ... + 14578.

It is an arithmetic number, because the mean of its divisors is an integer number (7103250).

Almost surely, 2^28384891 is an apocalyptic number.

28384891 is a deficient number, since it is larger than the sum of its proper divisors (28109).

28384891 is a wasteful number, since it uses less digits than its factorization.

28384891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28108.

The product of its digits is 110592, while the sum is 43.

The square root of 28384891 is about 5327.7472725346. The cubic root of 28384891 is about 305.0439460103.

The spelling of 28384891 in words is "twenty-eight million, three hundred eighty-four thousand, eight hundred ninety-one".