28789505 has 4 divisors (see below), whose sum is σ = 34547412. Its totient is φ = 23031600.

The previous prime is 28789493. The next prime is 28789511. The reversal of 28789505 is 50598782.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17707264 + 11082241 = 4208^2 + 3329^2 .

It is not a de Polignac number, because 28789505 - 2¹⁰ = 28788481 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2878946 + ... + 2878955.

It is an arithmetic number, because the mean of its divisors is an integer number (8636853).

Almost surely, 2^28789505 is an apocalyptic number.

It is an amenable number.

28789505 is a deficient number, since it is larger than the sum of its proper divisors (5757907).

28789505 is an equidigital number, since it uses as much as digits as its factorization.

28789505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5757906.

The product of its (nonzero) digits is 201600, while the sum is 44.

The square root of 28789505 is about 5365.5852430094. The cubic root of 28789505 is about 306.4865350194.

The spelling of 28789505 in words is "twenty-eight million, seven hundred eighty-nine thousand, five hundred five".