28339639 has 2 divisors, whose sum is σ = 28339640. Its totient is φ = 28339638.

The previous prime is 28339631. The next prime is 28339643. The reversal of 28339639 is 93693382.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28339639 - 2³ = 28339631 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28339595 and 28339604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28339631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14169819 + 14169820.

It is an arithmetic number, because the mean of its divisors is an integer number (14169820).

Almost surely, 2^28339639 is an apocalyptic number.

28339639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28339639 is an equidigital number, since it uses as much as digits as its factorization.

28339639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 43.

The square root of 28339639 is about 5323.4987555178. The cubic root of 28339639 is about 304.8817565478.

The spelling of 28339639 in words is "twenty-eight million, three hundred thirty-nine thousand, six hundred thirty-nine".