198840 has 32 divisors (see below), whose sum is σ = 596880. Its totient is φ = 52992.

The previous prime is 198839. The next prime is 198841. The reversal of 198840 is 48891.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (198839) and next prime (198841).

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

It is a junction number, because it is equal to n+sod(n) for n = 198798 and 198807.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 198840.

It is not an unprimeable number, because it can be changed into a prime (198841) 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 7 ways as a sum of consecutive naturals, for example, 709 + ... + 948.

2¹⁹⁸⁸⁴⁰ is an apocalyptic number.

198840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

198840 is an abundant number, since it is smaller than the sum of its proper divisors (398040).

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

198840 is a wasteful number, since it uses less digits than its factorization.

198840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1671 (or 1667 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 198840 is about 445.9147900664. The cubic root of 198840 is about 58.3670734514.

The spelling of 198840 in words is "one hundred ninety-eight thousand, eight hundred forty".