28635689 has 2 divisors, whose sum is σ = 28635690. Its totient is φ = 28635688.

The previous prime is 28635647. The next prime is 28635781. The reversal of 28635689 is 98653682.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26091664 + 2544025 = 5108^2 + 1595^2 .

It is a cyclic number.

It is not a de Polignac number, because 28635689 - 2⁸ = 28635433 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28635619) 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, 14317844 + 14317845.

It is an arithmetic number, because the mean of its divisors is an integer number (14317845).

Almost surely, 2^28635689 is an apocalyptic number.

It is an amenable number.

28635689 is a deficient number, since it is larger than the sum of its proper divisors (1).

28635689 is an equidigital number, since it uses as much as digits as its factorization.

28635689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 622080, while the sum is 47.

The square root of 28635689 is about 5351.2324748603. The cubic root of 28635689 is about 305.9397299671.

The spelling of 28635689 in words is "twenty-eight million, six hundred thirty-five thousand, six hundred eighty-nine".