28309139 has 2 divisors, whose sum is σ = 28309140. Its totient is φ = 28309138.

The previous prime is 28309129. The next prime is 28309217. The reversal of 28309139 is 93190382.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28309139 - 2¹⁶ = 28243603 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28309099 and 28309108.

It is not a weakly prime, because it can be changed into another prime (28309109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14154569 + 14154570.

It is an arithmetic number, because the mean of its divisors is an integer number (14154570).

Almost surely, 2^28309139 is an apocalyptic number.

28309139 is a deficient number, since it is larger than the sum of its proper divisors (1).

28309139 is an equidigital number, since it uses as much as digits as its factorization.

28309139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 28309139 is about 5320.6333269640. The cubic root of 28309139 is about 304.7723428806.

The spelling of 28309139 in words is "twenty-eight million, three hundred nine thousand, one hundred thirty-nine".