198 has 12 divisors (see below), whose sum is σ = 468. Its totient is φ = 60.

The previous prime is 197. The next prime is 199. The reversal of 198 is 891.

Adding to 198 its sum of digits (18), we get a cube (216 = 6^{3}).

198 divided by its sum of digits (18) gives a palindrome (11).

Adding to 198 its reverse (891), we get a square (1089 = 33^{2}).

It can be divided in two parts, 19 and 8, that added together give a cube (27 = 3^{3}).

198 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

198 is an esthetic number in base 13, because in such base its adjacent digits differ by 1.

It is an interprime number because it is at equal distance from previous prime (197) and next prime (199).

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 11 = 198 / (1 + 9 + 8).

198 is strictly pandigital in base 4.

It is a Curzon number.

It is a plaindrome in base 12 and base 13.

It is a nialpdrome in base 3, base 6, base 15 and base 16.

It is a self number, because there is not a number *n* which added to its sum of digits gives 198.

It is a congruent number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13 + ... + 23.

It is an arithmetic number, because the mean of its divisors is an integer number (39).

198 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 198, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (234).

198 is an abundant number, since it is smaller than the sum of its proper divisors (270).

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

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

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

The sum of its prime factors is 19 (or 16 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

The square root of 198 is about 14.0712472795. The cubic root of 198 is about 5.8284766833.

The spelling of 198 in words is "one hundred ninety-eight", and thus it is an aban number.

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