198819 has 6 divisors (see below), whose sum is σ = 287196. Its totient is φ = 132540.

The previous prime is 198817. The next prime is 198823. The reversal of 198819 is 918891.

It is not a de Polignac number, because 198819 - 2¹ = 198817 is a prime.

It is a super-2 number, since 2×198819² = 79057989522, which contains 22 as substring.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (198811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11037 + ... + 11054.

It is an arithmetic number, because the mean of its divisors is an integer number (47866).

2¹⁹⁸⁸¹⁹ is an apocalyptic number.

198819 is a deficient number, since it is larger than the sum of its proper divisors (88377).

198819 is a wasteful number, since it uses less digits than its factorization.

198819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22097 (or 22094 counting only the distinct ones).

The product of its digits is 5184, while the sum is 36.

The square root of 198819 is about 445.8912423450. The cubic root of 198819 is about 58.3650186139.

It can be divided in two parts, 19881 and 9, that multiplied together give a square (178929 = 423²).

The spelling of 198819 in words is "one hundred ninety-eight thousand, eight hundred nineteen".