1028666885 has 4 divisors (see below), whose sum is σ = 1234400268. Its totient is φ = 822933504.

The previous prime is 1028666843. The next prime is 1028666887. The reversal of 1028666885 is 5886668201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5886668201 = 55717 ⋅105653.

It can be written as a sum of positive squares in 2 ways, for example, as 210192004 + 818474881 = 14498^2 + 28609^2 .

It is a cyclic number.

It is not a de Polignac number, because 1028666885 - 2⁸ = 1028666629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1028666887) 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 in 3 ways as a sum of consecutive naturals, for example, 102866684 + ... + 102866693.

It is an arithmetic number, because the mean of its divisors is an integer number (308600067).

Almost surely, 2^1028666885 is an apocalyptic number.

It is an amenable number.

1028666885 is a deficient number, since it is larger than the sum of its proper divisors (205733383).

1028666885 is an equidigital number, since it uses as much as digits as its factorization.

1028666885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205733382.

The product of its (nonzero) digits is 1105920, while the sum is 50.

The square root of 1028666885 is about 32072.8371835109. The cubic root of 1028666885 is about 1009.4657452882.

The spelling of 1028666885 in words is "one billion, twenty-eight million, six hundred sixty-six thousand, eight hundred eighty-five".