208559891 has 2 divisors, whose sum is σ = 208559892. Its totient is φ = 208559890.

The previous prime is 208559887. The next prime is 208559951. The reversal of 208559891 is 198955802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 208559891 - 2² = 208559887 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (208559801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104279945 + 104279946.

It is an arithmetic number, because the mean of its divisors is an integer number (104279946).

Almost surely, 2^208559891 is an apocalyptic number.

208559891 is a deficient number, since it is larger than the sum of its proper divisors (1).

208559891 is an equidigital number, since it uses as much as digits as its factorization.

208559891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 47.

The square root of 208559891 is about 14441.6027850097. The cubic root of 208559891 is about 593.0303639517.

The spelling of 208559891 in words is "two hundred eight million, five hundred fifty-nine thousand, eight hundred ninety-one".