1998198181843 has 2 divisors, whose sum is σ = 1998198181844. Its totient is φ = 1998198181842.

The previous prime is 1998198181829. The next prime is 1998198181853. The reversal of 1998198181843 is 3481818918991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998198181843 is a prime.

It is not a weakly prime, because it can be changed into another prime (1998198181853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999099090921 + 999099090922.

It is an arithmetic number, because the mean of its divisors is an integer number (999099090922).

Almost surely, 2^{1998198181843} is an apocalyptic number.

1998198181843 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998198181843 is an equidigital number, since it uses as much as digits as its factorization.

1998198181843 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35831808, while the sum is 70.

The spelling of 1998198181843 in words is "one trillion, nine hundred ninety-eight billion, one hundred ninety-eight million, one hundred eighty-one thousand, eight hundred forty-three".