198705 has 16 divisors (see below), whose sum is σ = 342720. Its totient is φ = 97728.

The previous prime is 198701. The next prime is 198719. The reversal of 198705 is 507891.

It is not a de Polignac number, because 198705 - 2² = 198701 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 315 + ... + 704.

It is an arithmetic number, because the mean of its divisors is an integer number (21420).

2¹⁹⁸⁷⁰⁵ is an apocalyptic number.

198705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

198705 is a deficient number, since it is larger than the sum of its proper divisors (144015).

198705 is a wasteful number, since it uses less digits than its factorization.

198705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040.

The product of its (nonzero) digits is 2520, while the sum is 30.

The square root of 198705 is about 445.7633901522. The cubic root of 198705 is about 58.3538612560.

It can be divided in two parts, 198 and 705, that added together give a triangular number (903 = T₄₂).

The spelling of 198705 in words is "one hundred ninety-eight thousand, seven hundred five".