208685381 has 2 divisors, whose sum is σ = 208685382. Its totient is φ = 208685380.

The previous prime is 208685357. The next prime is 208685431. The reversal of 208685381 is 183586802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197402500 + 11282881 = 14050^2 + 3359^2 .

It is a cyclic number.

It is not a de Polignac number, because 208685381 - 2²⁶ = 141576517 is a prime.

It is a super-2 number, since 2×208685381² = 87099176486230322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208685681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104342690 + 104342691.

It is an arithmetic number, because the mean of its divisors is an integer number (104342691).

Almost surely, 2^208685381 is an apocalyptic number.

It is an amenable number.

208685381 is a deficient number, since it is larger than the sum of its proper divisors (1).

208685381 is an equidigital number, since it uses as much as digits as its factorization.

208685381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 92160, while the sum is 41.

The square root of 208685381 is about 14445.9468710085. The cubic root of 208685381 is about 593.1492817664.

The spelling of 208685381 in words is "two hundred eight million, six hundred eighty-five thousand, three hundred eighty-one".