198908657 has 2 divisors, whose sum is σ = 198908658. Its totient is φ = 198908656.

The previous prime is 198908621. The next prime is 198908719. The reversal of 198908657 is 756809891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 190329616 + 8579041 = 13796^2 + 2929^2 .

It is a cyclic number.

It is not a de Polignac number, because 198908657 - 2¹² = 198904561 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 198908599 and 198908608.

It is not a weakly prime, because it can be changed into another prime (198908257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99454328 + 99454329.

It is an arithmetic number, because the mean of its divisors is an integer number (99454329).

Almost surely, 2^198908657 is an apocalyptic number.

It is an amenable number.

198908657 is a deficient number, since it is larger than the sum of its proper divisors (1).

198908657 is an equidigital number, since it uses as much as digits as its factorization.

198908657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 53.

The square root of 198908657 is about 14103.4980412662. The cubic root of 198908657 is about 583.7379048860.

The spelling of 198908657 in words is "one hundred ninety-eight million, nine hundred eight thousand, six hundred fifty-seven".