28309289 has 2 divisors, whose sum is σ = 28309290. Its totient is φ = 28309288.

The previous prime is 28309277. The next prime is 28309319. The reversal of 28309289 is 98290382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28302400 + 6889 = 5320^2 + 83^2 .

It is a cyclic number.

It is not a de Polignac number, because 28309289 - 2⁴ = 28309273 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28309219) 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, 14154644 + 14154645.

It is an arithmetic number, because the mean of its divisors is an integer number (14154645).

Almost surely, 2^28309289 is an apocalyptic number.

It is an amenable number.

28309289 is a deficient number, since it is larger than the sum of its proper divisors (1).

28309289 is an equidigital number, since it uses as much as digits as its factorization.

28309289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 28309289 is about 5320.6474230116. The cubic root of 28309289 is about 304.7728811728.

The spelling of 28309289 in words is "twenty-eight million, three hundred nine thousand, two hundred eighty-nine".