28089391 has 8 divisors (see below), whose sum is σ = 32256000. Its totient is φ = 24191640.

The previous prime is 28089377. The next prime is 28089419. The reversal of 28089391 is 19398082.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28089391 - 2⁵ = 28089359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28089361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66991 + ... + 67408.

It is an arithmetic number, because the mean of its divisors is an integer number (4032000).

Almost surely, 2^28089391 is an apocalyptic number.

28089391 is a deficient number, since it is larger than the sum of its proper divisors (4166609).

28089391 is a wasteful number, since it uses less digits than its factorization.

28089391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134429.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 28089391 is about 5299.9425468584. The cubic root of 28089391 is about 303.9817012012.

The spelling of 28089391 in words is "twenty-eight million, eighty-nine thousand, three hundred ninety-one".