28087139 has 2 divisors, whose sum is σ = 28087140. Its totient is φ = 28087138.

The previous prime is 28087133. The next prime is 28087141. The reversal of 28087139 is 93178082.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28087139 - 2¹² = 28083043 is a prime.

Together with 28087141, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28087133) 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, 14043569 + 14043570.

It is an arithmetic number, because the mean of its divisors is an integer number (14043570).

Almost surely, 2^28087139 is an apocalyptic number.

28087139 is a deficient number, since it is larger than the sum of its proper divisors (1).

28087139 is an equidigital number, since it uses as much as digits as its factorization.

28087139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 28087139 is about 5299.7300874667. The cubic root of 28087139 is about 303.9735773145.

It can be divided in two parts, 28087 and 139, that multiplied together give a palindrome (3904093).

The spelling of 28087139 in words is "twenty-eight million, eighty-seven thousand, one hundred thirty-nine".