28292791 has 4 divisors (see below), whose sum is σ = 28633752. Its totient is φ = 27951832.

The previous prime is 28292773. The next prime is 28292807. The reversal of 28292791 is 19729282.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28292791 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28292701) 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, 170356 + ... + 170521.

It is an arithmetic number, because the mean of its divisors is an integer number (7158438).

Almost surely, 2^28292791 is an apocalyptic number.

28292791 is a deficient number, since it is larger than the sum of its proper divisors (340961).

28292791 is an equidigital number, since it uses as much as digits as its factorization.

28292791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340960.

The product of its digits is 36288, while the sum is 40.

The square root of 28292791 is about 5319.0968218298. The cubic root of 28292791 is about 304.7136648019.

The spelling of 28292791 in words is "twenty-eight million, two hundred ninety-two thousand, seven hundred ninety-one".