198868891 has 12 divisors (see below), whose sum is σ = 219933792. Its totient is φ = 179658336.

The previous prime is 198868889. The next prime is 198868909.

198868891 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 198868891 - 2¹ = 198868889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198868811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4576 + ... + 20461.

It is an arithmetic number, because the mean of its divisors is an integer number (18327816).

Almost surely, 2^198868891 is an apocalyptic number.

198868891 is a deficient number, since it is larger than the sum of its proper divisors (21064901).

198868891 is a wasteful number, since it uses less digits than its factorization.

198868891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25110 (or 25097 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 58.

The square root of 198868891 is about 14102.0881787060. The cubic root of 198868891 is about 583.6990018220.

The spelling of 198868891 in words is "one hundred ninety-eight million, eight hundred sixty-eight thousand, eight hundred ninety-one".