28286945 has 4 divisors (see below), whose sum is σ = 33944340. Its totient is φ = 22629552.

The previous prime is 28286939. The next prime is 28286957. The reversal of 28286945 is 54968282.

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 4977361 + 23309584 = 2231^2 + 4828^2 .

It is a cyclic number.

It is not a de Polignac number, because 28286945 - 2¹⁰ = 28285921 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28286896 and 28286905.

It is an unprimeable number.

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, 2828690 + ... + 2828699.

It is an arithmetic number, because the mean of its divisors is an integer number (8486085).

Almost surely, 2^28286945 is an apocalyptic number.

It is an amenable number.

28286945 is a deficient number, since it is larger than the sum of its proper divisors (5657395).

28286945 is an equidigital number, since it uses as much as digits as its factorization.

28286945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5657394.

The product of its digits is 276480, while the sum is 44.

The square root of 28286945 is about 5318.5472640562. The cubic root of 28286945 is about 304.6926761952.

The spelling of 28286945 in words is "twenty-eight million, two hundred eighty-six thousand, nine hundred forty-five".