198390 has 32 divisors (see below), whose sum is σ = 505440. Its totient is φ = 49664.

The previous prime is 198377. The next prime is 198391. The reversal of 198390 is 93891.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198391) by changing a digit.

198390 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 316 + ... + 704.

It is an arithmetic number, because the mean of its divisors is an integer number (15795).

2¹⁹⁸³⁹⁰ is an apocalyptic number.

198390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 198390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252720).

198390 is an abundant number, since it is smaller than the sum of its proper divisors (307050).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

198390 is a wasteful number, since it uses less digits than its factorization.

198390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 198390 is about 445.4099235536. The cubic root of 198390 is about 58.3230095109.

The spelling of 198390 in words is "one hundred ninety-eight thousand, three hundred ninety".