198019979 has 2 divisors, whose sum is σ = 198019980. Its totient is φ = 198019978.

The previous prime is 198019963. The next prime is 198020021. The reversal of 198019979 is 979910891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 198019979 - 2⁴ = 198019963 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 198019979.

It is not a weakly prime, because it can be changed into another prime (198019379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99009989 + 99009990.

It is an arithmetic number, because the mean of its divisors is an integer number (99009990).

Almost surely, 2^198019979 is an apocalyptic number.

198019979 is a deficient number, since it is larger than the sum of its proper divisors (1).

198019979 is an equidigital number, since it uses as much as digits as its factorization.

198019979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 367416, while the sum is 53.

The square root of 198019979 is about 14071.9571844147. The cubic root of 198019979 is about 582.8672715607.

The spelling of 198019979 in words is "one hundred ninety-eight million, nineteen thousand, nine hundred seventy-nine".