28917839 has 2 divisors, whose sum is σ = 28917840. Its totient is φ = 28917838.

The previous prime is 28917821. The next prime is 28917841. The reversal of 28917839 is 93871982.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28917839 - 2¹² = 28913743 is a prime.

Together with 28917841, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 28917793 and 28917802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28917439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14458919 + 14458920.

It is an arithmetic number, because the mean of its divisors is an integer number (14458920).

Almost surely, 2^28917839 is an apocalyptic number.

28917839 is a deficient number, since it is larger than the sum of its proper divisors (1).

28917839 is an equidigital number, since it uses as much as digits as its factorization.

28917839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 47.

The square root of 28917839 is about 5377.5309390091. The cubic root of 28917839 is about 306.9412648867.

The spelling of 28917839 in words is "twenty-eight million, nine hundred seventeen thousand, eight hundred thirty-nine".