198638 has 8 divisors (see below), whose sum is σ = 325080. Its totient is φ = 90280.

The previous prime is 198637. The next prime is 198641. The reversal of 198638 is 836891.

198638 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 198598 and 198607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198637) 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, 4493 + ... + 4536.

It is an arithmetic number, because the mean of its divisors is an integer number (40635).

2¹⁹⁸⁶³⁸ is an apocalyptic number.

198638 is a deficient number, since it is larger than the sum of its proper divisors (126442).

198638 is a wasteful number, since it uses less digits than its factorization.

198638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9042.

The product of its digits is 10368, while the sum is 35.

The square root of 198638 is about 445.6882318393. The cubic root of 198638 is about 58.3473018702.

The spelling of 198638 in words is "one hundred ninety-eight thousand, six hundred thirty-eight".