198783387891 has 24 divisors (see below), whose sum is σ = 317008351296. Its totient is φ = 119023272240.

The previous prime is 198783387851. The next prime is 198783387899.

It is a happy number.

198783387891 is a `hidden beast` number, since 1 + 9 + 87 + 83 + 387 + 8 + 91 = 666.

198783387891 is nontrivially palindromic in base 10.

198783387891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 198783387891 - 2³³ = 190193453299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198783387899) 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 in 23 ways as a sum of consecutive naturals, for example, 12087645 + ... + 12104078.

It is an arithmetic number, because the mean of its divisors is an integer number (13208681304).

Almost surely, 2^198783387891 is an apocalyptic number.

198783387891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

198783387891 is a deficient number, since it is larger than the sum of its proper divisors (118224963405).

198783387891 is a wasteful number, since it uses less digits than its factorization.

198783387891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24191823 (or 24191820 counting only the distinct ones).

The product of its digits is 146313216, while the sum is 72.

The spelling of 198783387891 in words is "one hundred ninety-eight billion, seven hundred eighty-three million, three hundred eighty-seven thousand, eight hundred ninety-one".