208664216641 has 2 divisors, whose sum is σ = 208664216642. Its totient is φ = 208664216640.

The previous prime is 208664216639. The next prime is 208664216669. The reversal of 208664216641 is 146612466802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161540490241 + 47123726400 = 401921^2 + 217080^2 .

It is a cyclic number.

It is not a de Polignac number, because 208664216641 - 2¹ = 208664216639 is a prime.

Together with 208664216639, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 208664216591 and 208664216600.

It is not a weakly prime, because it can be changed into another prime (208664216141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104332108320 + 104332108321.

It is an arithmetic number, because the mean of its divisors is an integer number (104332108321).

Almost surely, 2^208664216641 is an apocalyptic number.

It is an amenable number.

208664216641 is a deficient number, since it is larger than the sum of its proper divisors (1).

208664216641 is an equidigital number, since it uses as much as digits as its factorization.

208664216641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 663552, while the sum is 46.

The spelling of 208664216641 in words is "two hundred eight billion, six hundred sixty-four million, two hundred sixteen thousand, six hundred forty-one".