28884991 has 4 divisors (see below), whose sum is σ = 29079000. Its totient is φ = 28690984.

The previous prime is 28884983. The next prime is 28885009. The reversal of 28884991 is 19948882.

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 28884991 - 2³ = 28884983 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28881991) 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, 96781 + ... + 97078.

It is an arithmetic number, because the mean of its divisors is an integer number (7269750).

Almost surely, 2^28884991 is an apocalyptic number.

28884991 is a deficient number, since it is larger than the sum of its proper divisors (194009).

28884991 is a wasteful number, since it uses less digits than its factorization.

28884991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194008.

The product of its digits is 331776, while the sum is 49.

The square root of 28884991 is about 5374.4758814232. The cubic root of 28884991 is about 306.8250018580.

The spelling of 28884991 in words is "twenty-eight million, eight hundred eighty-four thousand, nine hundred ninety-one".