198978 has 16 divisors (see below), whose sum is σ = 428736. Its totient is φ = 61200.

The previous prime is 198977. The next prime is 198997. The reversal of 198978 is 879891.

198978 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (198971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1198 + ... + 1353.

It is an arithmetic number, because the mean of its divisors is an integer number (26796).

2¹⁹⁸⁹⁷⁸ is an apocalyptic number.

198978 is an abundant number, since it is smaller than the sum of its proper divisors (229758).

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

198978 is a wasteful number, since it uses less digits than its factorization.

198978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2569.

The product of its digits is 36288, while the sum is 42.

The square root of 198978 is about 446.0695013112. The cubic root of 198978 is about 58.3805730717.

It can be divided in two parts, 198 and 978, that added together give a triangular number (1176 = T₄₈).

The spelling of 198978 in words is "one hundred ninety-eight thousand, nine hundred seventy-eight".