28987191 has 6 divisors (see below), whose sum is σ = 41870400. Its totient is φ = 19324788.

The previous prime is 28987183. The next prime is 28987207. The reversal of 28987191 is 19178982.

It is not a de Polignac number, because 28987191 - 2³ = 28987183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28987111) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1610391 + ... + 1610408.

It is an arithmetic number, because the mean of its divisors is an integer number (6978400).

Almost surely, 2^28987191 is an apocalyptic number.

28987191 is a deficient number, since it is larger than the sum of its proper divisors (12883209).

28987191 is a wasteful number, since it uses less digits than its factorization.

28987191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3220805 (or 3220802 counting only the distinct ones).

The product of its digits is 72576, while the sum is 45.

The square root of 28987191 is about 5383.9753899883. The cubic root of 28987191 is about 307.1864422219.

The spelling of 28987191 in words is "twenty-eight million, nine hundred eighty-seven thousand, one hundred ninety-one".