198917 has 4 divisors (see below), whose sum is σ = 210636. Its totient is φ = 187200.

The previous prime is 198901. The next prime is 198929. The reversal of 198917 is 719891.

It is a Cunningham number, because it is equal to 446²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 719891 = 19 ⋅37889.

It can be written as a sum of positive squares in 2 ways, for example, as 155236 + 43681 = 394^2 + 209^2 .

It is a cyclic number.

It is not a de Polignac number, because 198917 - 2⁴ = 198901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 198917.

It is not an unprimeable number, because it can be changed into a prime (198937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5834 + ... + 5867.

It is an arithmetic number, because the mean of its divisors is an integer number (52659).

2¹⁹⁸⁹¹⁷ is an apocalyptic number.

198917 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

198917 is a deficient number, since it is larger than the sum of its proper divisors (11719).

198917 is a wasteful number, since it uses less digits than its factorization.

198917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11718.

The product of its digits is 4536, while the sum is 35.

The square root of 198917 is about 446.0011210748. The cubic root of 198917 is about 58.3746066182.

The spelling of 198917 in words is "one hundred ninety-eight thousand, nine hundred seventeen".