28247815 has 4 divisors (see below), whose sum is σ = 33897384. Its totient is φ = 22598248.

The previous prime is 28247809. The next prime is 28247831. The reversal of 28247815 is 51874282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51874282 = 2 ⋅25937141.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28247815 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2824777 + ... + 2824786.

It is an arithmetic number, because the mean of its divisors is an integer number (8474346).

Almost surely, 2^28247815 is an apocalyptic number.

28247815 is a deficient number, since it is larger than the sum of its proper divisors (5649569).

28247815 is an equidigital number, since it uses as much as digits as its factorization.

28247815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5649568.

The product of its digits is 35840, while the sum is 37.

The square root of 28247815 is about 5314.8673548829. The cubic root of 28247815 is about 304.5521151665.

The spelling of 28247815 in words is "twenty-eight million, two hundred forty-seven thousand, eight hundred fifteen".