198508139 has 2 divisors, whose sum is σ = 198508140. Its totient is φ = 198508138.

The previous prime is 198508129. The next prime is 198508153. The reversal of 198508139 is 931805891.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198508139 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 198508139.

It is not a weakly prime, because it can be changed into another prime (198508109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99254069 + 99254070.

It is an arithmetic number, because the mean of its divisors is an integer number (99254070).

Almost surely, 2^198508139 is an apocalyptic number.

198508139 is a deficient number, since it is larger than the sum of its proper divisors (1).

198508139 is an equidigital number, since it uses as much as digits as its factorization.

198508139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 44.

The square root of 198508139 is about 14089.2916429464. The cubic root of 198508139 is about 583.3458411105.

The spelling of 198508139 in words is "one hundred ninety-eight million, five hundred eight thousand, one hundred thirty-nine".