28508263 has 4 divisors (see below), whose sum is σ = 32580880. Its totient is φ = 24435648.

The previous prime is 28508261. The next prime is 28508267. The reversal of 28508263 is 36280582.

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 28508263 - 2¹ = 28508261 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 (28508261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2036298 + ... + 2036311.

It is an arithmetic number, because the mean of its divisors is an integer number (8145220).

Almost surely, 2^28508263 is an apocalyptic number.

28508263 is a deficient number, since it is larger than the sum of its proper divisors (4072617).

28508263 is an equidigital number, since it uses as much as digits as its factorization.

28508263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4072616.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 28508263 is about 5339.3129707857. The cubic root of 28508263 is about 305.4852546048.

The spelling of 28508263 in words is "twenty-eight million, five hundred eight thousand, two hundred sixty-three".