208890281 has 2 divisors, whose sum is σ = 208890282. Its totient is φ = 208890280.

The previous prime is 208890257. The next prime is 208890287. The reversal of 208890281 is 182098802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198105625 + 10784656 = 14075^2 + 3284^2 .

It is a cyclic number.

It is not a de Polignac number, because 208890281 - 2¹⁰ = 208889257 is a prime.

It is a super-2 number, since 2×208890281² = 87270298992517922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (208890287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104445140 + 104445141.

It is an arithmetic number, because the mean of its divisors is an integer number (104445141).

Almost surely, 2^208890281 is an apocalyptic number.

It is an amenable number.

208890281 is a deficient number, since it is larger than the sum of its proper divisors (1).

208890281 is an equidigital number, since it uses as much as digits as its factorization.

208890281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 208890281 is about 14453.0370856786. The cubic root of 208890281 is about 593.3433482788.

The spelling of 208890281 in words is "two hundred eight million, eight hundred ninety thousand, two hundred eighty-one".