28428445 has 4 divisors (see below), whose sum is σ = 34114140. Its totient is φ = 22742752.

The previous prime is 28428397. The next prime is 28428451. The reversal of 28428445 is 54482482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54482482 = 2 ⋅27241241.

It can be written as a sum of positive squares in 2 ways, for example, as 7689529 + 20738916 = 2773^2 + 4554^2 .

It is a cyclic number.

It is not a de Polignac number, because 28428445 - 2¹³ = 28420253 is a prime.

It is a congruent number.

It is an unprimeable number.

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, 2842840 + ... + 2842849.

It is an arithmetic number, because the mean of its divisors is an integer number (8528535).

Almost surely, 2^28428445 is an apocalyptic number.

It is an amenable number.

28428445 is a deficient number, since it is larger than the sum of its proper divisors (5685695).

28428445 is an equidigital number, since it uses as much as digits as its factorization.

28428445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5685694.

The product of its digits is 81920, while the sum is 37.

The square root of 28428445 is about 5331.8331744345. The cubic root of 28428445 is about 305.1998868885.

The spelling of 28428445 in words is "twenty-eight million, four hundred twenty-eight thousand, four hundred forty-five".