28042745 has 4 divisors (see below), whose sum is σ = 33651300. Its totient is φ = 22434192.

The previous prime is 28042733. The next prime is 28042787. The reversal of 28042745 is 54724082.

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 10936249 + 17106496 = 3307^2 + 4136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28042745 is a prime.

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, 2804270 + ... + 2804279.

It is an arithmetic number, because the mean of its divisors is an integer number (8412825).

Almost surely, 2^28042745 is an apocalyptic number.

It is an amenable number.

28042745 is a deficient number, since it is larger than the sum of its proper divisors (5608555).

28042745 is an equidigital number, since it uses as much as digits as its factorization.

28042745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5608554.

The product of its (nonzero) digits is 17920, while the sum is 32.

The square root of 28042745 is about 5295.5401046541. The cubic root of 28042745 is about 303.8133412362.

The spelling of 28042745 in words is "twenty-eight million, forty-two thousand, seven hundred forty-five".