28847791 has 4 divisors (see below), whose sum is σ = 32968912. Its totient is φ = 24726672.

The previous prime is 28847783. The next prime is 28847821. The reversal of 28847791 is 19774882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19774882 = 2 ⋅9887441.

It is a cyclic number.

It is not a de Polignac number, because 28847791 - 2³ = 28847783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28847771) 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, 2060550 + ... + 2060563.

It is an arithmetic number, because the mean of its divisors is an integer number (8242228).

Almost surely, 2^28847791 is an apocalyptic number.

28847791 is a deficient number, since it is larger than the sum of its proper divisors (4121121).

28847791 is an equidigital number, since it uses as much as digits as its factorization.

28847791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4121120.

The product of its digits is 225792, while the sum is 46.

The square root of 28847791 is about 5371.0139638619. The cubic root of 28847791 is about 306.6932287694.

The spelling of 28847791 in words is "twenty-eight million, eight hundred forty-seven thousand, seven hundred ninety-one".