28508489 has 4 divisors (see below), whose sum is σ = 29203860. Its totient is φ = 27813120.

The previous prime is 28508453. The next prime is 28508503. The reversal of 28508489 is 98480582.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98480582 = 2 ⋅49240291.

It can be written as a sum of positive squares in 2 ways, for example, as 840889 + 27667600 = 917^2 + 5260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28508489 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28508419) 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, 347624 + ... + 347705.

It is an arithmetic number, because the mean of its divisors is an integer number (7300965).

Almost surely, 2^28508489 is an apocalyptic number.

It is an amenable number.

28508489 is a deficient number, since it is larger than the sum of its proper divisors (695371).

28508489 is an equidigital number, since it uses as much as digits as its factorization.

28508489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695370.

The product of its (nonzero) digits is 184320, while the sum is 44.

The square root of 28508489 is about 5339.3341345153. The cubic root of 28508489 is about 305.4860618501.

The spelling of 28508489 in words is "twenty-eight million, five hundred eight thousand, four hundred eighty-nine".