198975266557 has 2 divisors, whose sum is σ = 198975266558. Its totient is φ = 198975266556.

The previous prime is 198975266537. The next prime is 198975266561. The reversal of 198975266557 is 755662579891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167435637721 + 31539628836 = 409189^2 + 177594^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198975266557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198975266507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99487633278 + 99487633279.

It is an arithmetic number, because the mean of its divisors is an integer number (99487633279).

Almost surely, 2^198975266557 is an apocalyptic number.

It is an amenable number.

198975266557 is a deficient number, since it is larger than the sum of its proper divisors (1).

198975266557 is an equidigital number, since it uses as much as digits as its factorization.

198975266557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768000, while the sum is 70.

The spelling of 198975266557 in words is "one hundred ninety-eight billion, nine hundred seventy-five million, two hundred sixty-six thousand, five hundred fifty-seven".