198109587 has 16 divisors (see below), whose sum is σ = 285304320. Its totient is φ = 121553952.

The previous prime is 198109579. The next prime is 198109591. The reversal of 198109587 is 785901891.

It is not a de Polignac number, because 198109587 - 2³ = 198109579 is a prime.

It is a super-2 number, since 2×198109587² = 78494816922621138, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (198109567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6214 + ... + 20852.

It is an arithmetic number, because the mean of its divisors is an integer number (17831520).

Almost surely, 2^198109587 is an apocalyptic number.

198109587 is a deficient number, since it is larger than the sum of its proper divisors (87194733).

198109587 is a wasteful number, since it uses less digits than its factorization.

198109587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15002.

The product of its (nonzero) digits is 181440, while the sum is 48.

The square root of 198109587 is about 14075.1407452998. The cubic root of 198109587 is about 582.9551780006.

The spelling of 198109587 in words is "one hundred ninety-eight million, one hundred nine thousand, five hundred eighty-seven".