198523 has 4 divisors (see below), whose sum is σ = 213808. Its totient is φ = 183240.

The previous prime is 198503. The next prime is 198529. The reversal of 198523 is 325891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 198523 - 2⁵ = 198491 is a prime.

It is a super-2 number, since 2×198523² = 78822763058, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 198491 and 198500.

It is not an unprimeable number, because it can be changed into a prime (198529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7623 + ... + 7648.

It is an arithmetic number, because the mean of its divisors is an integer number (53452).

2¹⁹⁸⁵²³ is an apocalyptic number.

198523 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

198523 is a deficient number, since it is larger than the sum of its proper divisors (15285).

198523 is a wasteful number, since it uses less digits than its factorization.

198523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15284.

The product of its digits is 2160, while the sum is 28.

The square root of 198523 is about 445.5591992093. The cubic root of 198523 is about 58.3360397837.

The spelling of 198523 in words is "one hundred ninety-eight thousand, five hundred twenty-three".