28056439 has 2 divisors, whose sum is σ = 28056440. Its totient is φ = 28056438.

The previous prime is 28056437. The next prime is 28056461. The reversal of 28056439 is 93465082.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28056439 - 2¹ = 28056437 is a prime.

Together with 28056437, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 28056398 and 28056407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28056437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14028219 + 14028220.

It is an arithmetic number, because the mean of its divisors is an integer number (14028220).

Almost surely, 2^28056439 is an apocalyptic number.

28056439 is a deficient number, since it is larger than the sum of its proper divisors (1).

28056439 is an equidigital number, since it uses as much as digits as its factorization.

28056439 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 28056439 is about 5296.8329216618. The cubic root of 28056439 is about 303.8627865011.

The spelling of 28056439 in words is "twenty-eight million, fifty-six thousand, four hundred thirty-nine".