208218681 has 48 divisors (see below), whose sum is σ = 346102848. Its totient is φ = 124027200.

The previous prime is 208218679. The next prime is 208218691. The reversal of 208218681 is 186812802.

It is not a de Polignac number, because 208218681 - 2¹ = 208218679 is a prime.

It is a super-2 number, since 2×208218681² = 86710038234759522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (208218631) 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 47 ways as a sum of consecutive naturals, for example, 162415 + ... + 163691.

It is an arithmetic number, because the mean of its divisors is an integer number (7210476).

Almost surely, 2^208218681 is an apocalyptic number.

It is an amenable number.

208218681 is a deficient number, since it is larger than the sum of its proper divisors (137884167).

208218681 is a wasteful number, since it uses less digits than its factorization.

208218681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1364 (or 1352 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 208218681 is about 14429.7845098255. The cubic root of 208218681 is about 592.7067824952.

The spelling of 208218681 in words is "two hundred eight million, two hundred eighteen thousand, six hundred eighty-one".