198295397561 has 2 divisors, whose sum is σ = 198295397562. Its totient is φ = 198295397560.

The previous prime is 198295397507. The next prime is 198295397563. The reversal of 198295397561 is 165793592891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186089567161 + 12205830400 = 431381^2 + 110480^2 .

It is a cyclic number.

It is not a de Polignac number, because 198295397561 - 2¹⁴ = 198295381177 is a prime.

Together with 198295397563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (198295397563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99147698780 + 99147698781.

It is an arithmetic number, because the mean of its divisors is an integer number (99147698781).

Almost surely, 2^198295397561 is an apocalyptic number.

It is an amenable number.

198295397561 is a deficient number, since it is larger than the sum of its proper divisors (1).

198295397561 is an equidigital number, since it uses as much as digits as its factorization.

198295397561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36741600, while the sum is 65.

The spelling of 198295397561 in words is "one hundred ninety-eight billion, two hundred ninety-five million, three hundred ninety-seven thousand, five hundred sixty-one".