28508839 has 2 divisors, whose sum is σ = 28508840. Its totient is φ = 28508838.

The previous prime is 28508819. The next prime is 28508849. The reversal of 28508839 is 93880582.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28508839 - 2⁵ = 28508807 is a prime.

It is a super-2 number, since 2×28508839² = 1625507802255842, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28508795 and 28508804.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28508819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14254419 + 14254420.

It is an arithmetic number, because the mean of its divisors is an integer number (14254420).

Almost surely, 2^28508839 is an apocalyptic number.

28508839 is a deficient number, since it is larger than the sum of its proper divisors (1).

28508839 is an equidigital number, since it uses as much as digits as its factorization.

28508839 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 28508839 is about 5339.3669100372. The cubic root of 28508839 is about 305.4873120003.

The spelling of 28508839 in words is "twenty-eight million, five hundred eight thousand, eight hundred thirty-nine".