28089445 has 4 divisors (see below), whose sum is σ = 33707340. Its totient is φ = 22471552.

The previous prime is 28089443. The next prime is 28089461. The reversal of 28089445 is 54498082.

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 5678689 + 22410756 = 2383^2 + 4734^2 .

It is a cyclic number.

It is not a de Polignac number, because 28089445 - 2¹ = 28089443 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28089398 and 28089407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28089443) 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, 2808940 + ... + 2808949.

It is an arithmetic number, because the mean of its divisors is an integer number (8426835).

Almost surely, 2^28089445 is an apocalyptic number.

It is an amenable number.

28089445 is a deficient number, since it is larger than the sum of its proper divisors (5617895).

28089445 is an equidigital number, since it uses as much as digits as its factorization.

28089445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5617894.

The product of its (nonzero) digits is 92160, while the sum is 40.

The square root of 28089445 is about 5299.9476412508. The cubic root of 28089445 is about 303.9818959960.

The spelling of 28089445 in words is "twenty-eight million, eighty-nine thousand, four hundred forty-five".