28564591 has 10 divisors (see below), whose sum is σ = 31436960. Its totient is φ = 25954500.

The previous prime is 28564559. The next prime is 28564621. The reversal of 28564591 is 19546582.

It is not a de Polignac number, because 28564591 - 2⁵ = 28564559 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 (28564541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 13666 + ... + 15616.

It is an arithmetic number, because the mean of its divisors is an integer number (3143696).

Almost surely, 2^28564591 is an apocalyptic number.

28564591 is a deficient number, since it is larger than the sum of its proper divisors (2872369).

28564591 is an frugal number, since it uses more digits than its factorization.

28564591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995 (or 1962 counting only the distinct ones).

The product of its digits is 86400, while the sum is 40.

The square root of 28564591 is about 5344.5852037366. The cubic root of 28564591 is about 305.6863197345.

Subtracting from 28564591 its reverse (19546582), we obtain a square (9018009 = 3003²).

It can be divided in two parts, 2856 and 4591, that added together give a palindrome (7447).

The spelling of 28564591 in words is "twenty-eight million, five hundred sixty-four thousand, five hundred ninety-one".