198818887 has 2 divisors, whose sum is σ = 198818888. Its totient is φ = 198818886.

The previous prime is 198818861. The next prime is 198818897. The reversal of 198818887 is 788818891.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198818887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198818827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99409443 + 99409444.

It is an arithmetic number, because the mean of its divisors is an integer number (99409444).

Almost surely, 2^198818887 is an apocalyptic number.

198818887 is a deficient number, since it is larger than the sum of its proper divisors (1).

198818887 is an equidigital number, since it uses as much as digits as its factorization.

198818887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2064384, while the sum is 58.

The square root of 198818887 is about 14100.3151383223. The cubic root of 198818887 is about 583.6500755648.

The spelling of 198818887 in words is "one hundred ninety-eight million, eight hundred eighteen thousand, eight hundred eighty-seven".