198040891 has 2 divisors, whose sum is σ = 198040892. Its totient is φ = 198040890.

The previous prime is 198040883. The next prime is 198040903.

198040891 is nontrivially palindromic in base 10.

It is a weak prime.

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 198040891 - 2³ = 198040883 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (198040091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99020445 + 99020446.

It is an arithmetic number, because the mean of its divisors is an integer number (99020446).

Almost surely, 2^198040891 is an apocalyptic number.

198040891 is a deficient number, since it is larger than the sum of its proper divisors (1).

198040891 is an equidigital number, since it uses as much as digits as its factorization.

198040891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 198040891 is about 14072.7002028751. The cubic root of 198040891 is about 582.8877888361.

The spelling of 198040891 in words is "one hundred ninety-eight million, forty thousand, eight hundred ninety-one".