198985705 has 4 divisors (see below), whose sum is σ = 238782852. Its totient is φ = 159188560.

The previous prime is 198985693. The next prime is 198985723. The reversal of 198985705 is 507589891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 507589891 = 683 ⋅743177.

It can be written as a sum of positive squares in 2 ways, for example, as 84345856 + 114639849 = 9184^2 + 10707^2 .

It is not a de Polignac number, because 198985705 - 2²³ = 190597097 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 19898566 + ... + 19898575.

It is an arithmetic number, because the mean of its divisors is an integer number (59695713).

Almost surely, 2^198985705 is an apocalyptic number.

It is an amenable number.

198985705 is a deficient number, since it is larger than the sum of its proper divisors (39797147).

198985705 is an equidigital number, since it uses as much as digits as its factorization.

198985705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39797146.

The product of its (nonzero) digits is 907200, while the sum is 52.

The square root of 198985705 is about 14106.2292977252. The cubic root of 198985705 is about 583.8132661646.

The spelling of 198985705 in words is "one hundred ninety-eight million, nine hundred eighty-five thousand, seven hundred five".