208991023 has 12 divisors (see below), whose sum is σ = 219735880. Its totient is φ = 198719136.

The previous prime is 208990993. The next prime is 208991033. The reversal of 208991023 is 320199802.

It is a de Polignac number, because none of the positive numbers 2^k-208991023 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 208991023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208991033) 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 in 11 ways as a sum of consecutive naturals, for example, 54493 + ... + 58201.

Almost surely, 2^208991023 is an apocalyptic number.

208991023 is a deficient number, since it is larger than the sum of its proper divisors (10744857).

208991023 is an equidigital number, since it uses as much as digits as its factorization.

208991023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3834 (or 3805 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 208991023 is about 14456.5218154299. The cubic root of 208991023 is about 593.4387173065.

The spelling of 208991023 in words is "two hundred eight million, nine hundred ninety-one thousand, twenty-three".