208112661697 has 2 divisors, whose sum is σ = 208112661698. Its totient is φ = 208112661696.

The previous prime is 208112661689. The next prime is 208112661733. The reversal of 208112661697 is 796166211802.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 170568174001 + 37544487696 = 412999^2 + 193764^2 .

It is a cyclic number.

It is not a de Polignac number, because 208112661697 - 2³ = 208112661689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 208112661697.

It is not a weakly prime, because it can be changed into another prime (208112661797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104056330848 + 104056330849.

It is an arithmetic number, because the mean of its divisors is an integer number (104056330849).

Almost surely, 2^208112661697 is an apocalyptic number.

It is an amenable number.

208112661697 is a deficient number, since it is larger than the sum of its proper divisors (1).

208112661697 is an equidigital number, since it uses as much as digits as its factorization.

208112661697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 49.

The spelling of 208112661697 in words is "two hundred eight billion, one hundred twelve million, six hundred sixty-one thousand, six hundred ninety-seven".