28389943 has 4 divisors (see below), whose sum is σ = 28411240. Its totient is φ = 28368648.

The previous prime is 28389931. The next prime is 28389947. The reversal of 28389943 is 34998382.

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

It is a cyclic number.

It is not a de Polignac number, because 28389943 - 2¹³ = 28381751 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28389893 and 28389902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28389947) 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, 8505 + ... + 11362.

It is an arithmetic number, because the mean of its divisors is an integer number (7102810).

Almost surely, 2^28389943 is an apocalyptic number.

28389943 is a deficient number, since it is larger than the sum of its proper divisors (21297).

28389943 is a wasteful number, since it uses less digits than its factorization.

28389943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21296.

The product of its digits is 373248, while the sum is 46.

The square root of 28389943 is about 5328.2213730287. The cubic root of 28389943 is about 305.0620423818.

The spelling of 28389943 in words is "twenty-eight million, three hundred eighty-nine thousand, nine hundred forty-three".