28727845 has 4 divisors (see below), whose sum is σ = 34473420. Its totient is φ = 22982272.

The previous prime is 28727843. The next prime is 28727849. The reversal of 28727845 is 54872782.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5166529 + 23561316 = 2273^2 + 4854^2 .

It is a cyclic number.

It is not a de Polignac number, because 28727845 - 2¹ = 28727843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28727843) 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 3 ways as a sum of consecutive naturals, for example, 2872780 + ... + 2872789.

It is an arithmetic number, because the mean of its divisors is an integer number (8618355).

Almost surely, 2^28727845 is an apocalyptic number.

It is an amenable number.

28727845 is a deficient number, since it is larger than the sum of its proper divisors (5745575).

28727845 is an equidigital number, since it uses as much as digits as its factorization.

28727845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5745574.

The product of its digits is 250880, while the sum is 43.

The square root of 28727845 is about 5359.8362848132. The cubic root of 28727845 is about 306.2675725027.

The spelling of 28727845 in words is "twenty-eight million, seven hundred twenty-seven thousand, eight hundred forty-five".