28791047 has 6 divisors (see below), whose sum is σ = 30584568. Its totient is φ = 27097184.

The previous prime is 28791041. The next prime is 28791073. The reversal of 28791047 is 74019782.

It is not a de Polignac number, because 28791047 - 2¹⁰ = 28790023 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28791047.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28791041) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 49523 + ... + 50100.

It is an arithmetic number, because the mean of its divisors is an integer number (5097428).

Almost surely, 2^28791047 is an apocalyptic number.

28791047 is a deficient number, since it is larger than the sum of its proper divisors (1793521).

28791047 is an equidigital number, since it uses as much as digits as its factorization.

28791047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99657 (or 99640 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 28791047 is about 5365.7289346369. The cubic root of 28791047 is about 306.4920068491.

The spelling of 28791047 in words is "twenty-eight million, seven hundred ninety-one thousand, forty-seven".