198591 has 8 divisors (see below), whose sum is σ = 270000. Its totient is φ = 129792.

The previous prime is 198589. The next prime is 198593. The reversal of 198591 is 195891.

It is an interprime number because it is at equal distance from previous prime (198589) and next prime (198593).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 198591 - 2¹ = 198589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 466 + ... + 783.

It is an arithmetic number, because the mean of its divisors is an integer number (33750).

2¹⁹⁸⁵⁹¹ is an apocalyptic number.

198591 is a deficient number, since it is larger than the sum of its proper divisors (71409).

198591 is a wasteful number, since it uses less digits than its factorization.

198591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305.

The product of its digits is 3240, while the sum is 33.

The square root of 198591 is about 445.6355012788. The cubic root of 198591 is about 58.3426996298.

The spelling of 198591 in words is "one hundred ninety-eight thousand, five hundred ninety-one".