198390442891 has 16 divisors (see below), whose sum is σ = 205907466240. Its totient is φ = 191028277440.

The previous prime is 198390442889. The next prime is 198390442897. The reversal of 198390442891 is 198244093891.

It is a cyclic number.

It is not a de Polignac number, because 198390442891 - 2¹ = 198390442889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198390442897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 948280 + ... + 1138426.

It is an arithmetic number, because the mean of its divisors is an integer number (12869216640).

Almost surely, 2^198390442891 is an apocalyptic number.

198390442891 is a deficient number, since it is larger than the sum of its proper divisors (7517023349).

198390442891 is a wasteful number, since it uses less digits than its factorization.

198390442891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190554.

The product of its (nonzero) digits is 4478976, while the sum is 58.

The spelling of 198390442891 in words is "one hundred ninety-eight billion, three hundred ninety million, four hundred forty-two thousand, eight hundred ninety-one".