198497585794861 has 2 divisors, whose sum is σ = 198497585794862. Its totient is φ = 198497585794860.

The previous prime is 198497585794853. The next prime is 198497585794931. The reversal of 198497585794861 is 168497585794891.

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., 168633339092100 + 29864246702761 = 12985890^2 + 5464819^2 .

It is an emirp because it is prime and its reverse (168497585794891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198497585794861 - 2³ = 198497585794853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198497585794801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99248792897430 + 99248792897431.

It is an arithmetic number, because the mean of its divisors is an integer number (99248792897431).

Almost surely, 2^{198497585794861} is an apocalyptic number.

It is an amenable number.

198497585794861 is a deficient number, since it is larger than the sum of its proper divisors (1).

198497585794861 is an equidigital number, since it uses as much as digits as its factorization.

198497585794861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43893964800, while the sum is 91.

The spelling of 198497585794861 in words is "one hundred ninety-eight trillion, four hundred ninety-seven billion, five hundred eighty-five million, seven hundred ninety-four thousand, eight hundred sixty-one".