198841691 has 2 divisors, whose sum is σ = 198841692. Its totient is φ = 198841690.

The previous prime is 198841681. The next prime is 198841697. The reversal of 198841691 is 196148891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 198841691 - 2⁶ = 198841627 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (198841697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99420845 + 99420846.

It is an arithmetic number, because the mean of its divisors is an integer number (99420846).

Almost surely, 2^198841691 is an apocalyptic number.

198841691 is a deficient number, since it is larger than the sum of its proper divisors (1).

198841691 is an equidigital number, since it uses as much as digits as its factorization.

198841691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 47.

The square root of 198841691 is about 14101.1237495456. The cubic root of 198841691 is about 583.6723890846.

The spelling of 198841691 in words is "one hundred ninety-eight million, eight hundred forty-one thousand, six hundred ninety-one".