28857139 has 2 divisors, whose sum is σ = 28857140. Its totient is φ = 28857138.

The previous prime is 28857137. The next prime is 28857193. The reversal of 28857139 is 93175882.

Together with next prime (28857193) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28857139 - 2¹ = 28857137 is a prime.

Together with 28857137, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 28857095 and 28857104.

It is not a weakly prime, because it can be changed into another prime (28857131) 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, 14428569 + 14428570.

It is an arithmetic number, because the mean of its divisors is an integer number (14428570).

Almost surely, 2^28857139 is an apocalyptic number.

28857139 is a deficient number, since it is larger than the sum of its proper divisors (1).

28857139 is an equidigital number, since it uses as much as digits as its factorization.

28857139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 43.

The square root of 28857139 is about 5371.8841201202. The cubic root of 28857139 is about 306.7263527231.

The spelling of 28857139 in words is "twenty-eight million, eight hundred fifty-seven thousand, one hundred thirty-nine".