28280015 has 4 divisors (see below), whose sum is σ = 33936024. Its totient is φ = 22624008.

The previous prime is 28279997. The next prime is 28280047. The reversal of 28280015 is 51008282.

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 28280015 - 2¹⁶ = 28214479 is a prime.

It is a Duffinian number.

It is a congruent 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, 2827997 + ... + 2828006.

It is an arithmetic number, because the mean of its divisors is an integer number (8484006).

Almost surely, 2^28280015 is an apocalyptic number.

28280015 is a deficient number, since it is larger than the sum of its proper divisors (5656009).

28280015 is an equidigital number, since it uses as much as digits as its factorization.

28280015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5656008.

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 28280015 is about 5317.8957304558. The cubic root of 28280015 is about 304.6677920104.

Adding to 28280015 its reverse (51008282), we get a palindrome (79288297).

The spelling of 28280015 in words is "twenty-eight million, two hundred eighty thousand, fifteen".