28564331 has 4 divisors (see below), whose sum is σ = 29261064. Its totient is φ = 27867600.

The previous prime is 28564313. The next prime is 28564337. The reversal of 28564331 is 13346582.

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

It is a cyclic number.

It is not a de Polignac number, because 28564331 - 2¹⁸ = 28302187 is a prime.

It is a super-2 number, since 2×28564331² = 1631842010955122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28564337) 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 3 ways as a sum of consecutive naturals, for example, 348305 + ... + 348386.

It is an arithmetic number, because the mean of its divisors is an integer number (7315266).

Almost surely, 2^28564331 is an apocalyptic number.

28564331 is a deficient number, since it is larger than the sum of its proper divisors (696733).

28564331 is an equidigital number, since it uses as much as digits as its factorization.

28564331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696732.

The product of its digits is 17280, while the sum is 32.

The square root of 28564331 is about 5344.5608799975. The cubic root of 28564331 is about 305.6853922612.

The spelling of 28564331 in words is "twenty-eight million, five hundred sixty-four thousand, three hundred thirty-one".