208131894607697 has 2 divisors, whose sum is σ = 208131894607698. Its totient is φ = 208131894607696.

The previous prime is 208131894607691. The next prime is 208131894607717. The reversal of 208131894607697 is 796706498131802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126445167206656 + 81686727401041 = 11244784^2 + 9038071^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208131894607697 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 208131894607697.

It is not a weakly prime, because it can be changed into another prime (208131894607691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104065947303848 + 104065947303849.

It is an arithmetic number, because the mean of its divisors is an integer number (104065947303849).

Almost surely, 2^{208131894607697} is an apocalyptic number.

It is an amenable number.

208131894607697 is a deficient number, since it is larger than the sum of its proper divisors (1).

208131894607697 is an equidigital number, since it uses as much as digits as its factorization.

208131894607697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 219469824, while the sum is 71.

The spelling of 208131894607697 in words is "two hundred eight trillion, one hundred thirty-one billion, eight hundred ninety-four million, six hundred seven thousand, six hundred ninety-seven".