28228591 has 8 divisors (see below), whose sum is σ = 28641600. Its totient is φ = 27818400.

The previous prime is 28228573. The next prime is 28228621. The reversal of 28228591 is 19582282.

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

It is a cyclic number.

It is not a de Polignac number, because 28228591 - 2²¹ = 26131439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28228591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28228391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26650 + ... + 27688.

It is an arithmetic number, because the mean of its divisors is an integer number (3580200).

Almost surely, 2^28228591 is an apocalyptic number.

28228591 is a deficient number, since it is larger than the sum of its proper divisors (413009).

28228591 is a wasteful number, since it uses less digits than its factorization.

28228591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1409.

The product of its digits is 23040, while the sum is 37.

The square root of 28228591 is about 5313.0585353448. The cubic root of 28228591 is about 304.4830120223.

It can be divided in two parts, 282285 and 91, that added together give a triangular number (282376 = T₇₅₁).

The spelling of 28228591 in words is "twenty-eight million, two hundred twenty-eight thousand, five hundred ninety-one".