209085871097 has 2 divisors, whose sum is σ = 209085871098. Its totient is φ = 209085871096.

The previous prime is 209085871087. The next prime is 209085871129. The reversal of 209085871097 is 790178580902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108200865721 + 100885005376 = 328939^2 + 317624^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209085871097 is a prime.

It is not a weakly prime, because it can be changed into another prime (209085871037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104542935548 + 104542935549.

It is an arithmetic number, because the mean of its divisors is an integer number (104542935549).

Almost surely, 2^209085871097 is an apocalyptic number.

It is an amenable number.

209085871097 is a deficient number, since it is larger than the sum of its proper divisors (1).

209085871097 is an equidigital number, since it uses as much as digits as its factorization.

209085871097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2540160, while the sum is 56.

The spelling of 209085871097 in words is "two hundred nine billion, eighty-five million, eight hundred seventy-one thousand, ninety-seven".