198724979 has 2 divisors, whose sum is σ = 198724980. Its totient is φ = 198724978.

The previous prime is 198724969. The next prime is 198725017. The reversal of 198724979 is 979427891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 198724979 - 2⁴ = 198724963 is a prime.

It is not a weakly prime, because it can be changed into another prime (198724969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99362489 + 99362490.

It is an arithmetic number, because the mean of its divisors is an integer number (99362490).

Almost surely, 2^198724979 is an apocalyptic number.

198724979 is a deficient number, since it is larger than the sum of its proper divisors (1).

198724979 is an equidigital number, since it uses as much as digits as its factorization.

198724979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 56.

The square root of 198724979 is about 14096.9847485198. The cubic root of 198724979 is about 583.5581694021.

The spelling of 198724979 in words is "one hundred ninety-eight million, seven hundred twenty-four thousand, nine hundred seventy-nine".