28445639 has 2 divisors, whose sum is σ = 28445640. Its totient is φ = 28445638.

The previous prime is 28445633. The next prime is 28445689. The reversal of 28445639 is 93654482.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28445639 - 2⁴ = 28445623 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28445596 and 28445605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28445633) 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 as a sum of consecutive naturals, namely, 14222819 + 14222820.

It is an arithmetic number, because the mean of its divisors is an integer number (14222820).

Almost surely, 2^28445639 is an apocalyptic number.

28445639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28445639 is an equidigital number, since it uses as much as digits as its factorization.

28445639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 207360, while the sum is 41.

The square root of 28445639 is about 5333.4453217409. The cubic root of 28445639 is about 305.2614044901.

The spelling of 28445639 in words is "twenty-eight million, four hundred forty-five thousand, six hundred thirty-nine".