28549591 has 4 divisors (see below), whose sum is σ = 32628112. Its totient is φ = 24471072.

The previous prime is 28549561. The next prime is 28549621. The reversal of 28549591 is 19594582.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (28549561) and next prime (28549621).

It is a cyclic number.

It is not a de Polignac number, because 28549591 - 2¹⁹ = 28025303 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 (28549501) 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, 2039250 + ... + 2039263.

It is an arithmetic number, because the mean of its divisors is an integer number (8157028).

Almost surely, 2^28549591 is an apocalyptic number.

28549591 is a deficient number, since it is larger than the sum of its proper divisors (4078521).

28549591 is an equidigital number, since it uses as much as digits as its factorization.

28549591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4078520.

The product of its digits is 129600, while the sum is 43.

The square root of 28549591 is about 5343.1817300182. The cubic root of 28549591 is about 305.6328024544.

The spelling of 28549591 in words is "twenty-eight million, five hundred forty-nine thousand, five hundred ninety-one".