28747643 has 4 divisors (see below), whose sum is σ = 28828080. Its totient is φ = 28667208.

The previous prime is 28747577. The next prime is 28747651. The reversal of 28747643 is 34674782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34674782 = 2 ⋅17337391.

It is a cyclic number.

It is not a de Polignac number, because 28747643 - 2⁸ = 28747387 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 28747643.

It is not an unprimeable number, because it can be changed into a prime (28747843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39680 + ... + 40397.

It is an arithmetic number, because the mean of its divisors is an integer number (7207020).

Almost surely, 2^28747643 is an apocalyptic number.

28747643 is a deficient number, since it is larger than the sum of its proper divisors (80437).

28747643 is an equidigital number, since it uses as much as digits as its factorization.

28747643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80436.

The product of its digits is 225792, while the sum is 41.

The square root of 28747643 is about 5361.6828514935. The cubic root of 28747643 is about 306.3379118435.

The spelling of 28747643 in words is "twenty-eight million, seven hundred forty-seven thousand, six hundred forty-three".