198728839 has 2 divisors, whose sum is σ = 198728840. Its totient is φ = 198728838.

The previous prime is 198728837. The next prime is 198728857. The reversal of 198728839 is 938827891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 198728839 - 2¹ = 198728837 is a prime.

Together with 198728837, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 198728839.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198728837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99364419 + 99364420.

It is an arithmetic number, because the mean of its divisors is an integer number (99364420).

Almost surely, 2^198728839 is an apocalyptic number.

198728839 is a deficient number, since it is larger than the sum of its proper divisors (1).

198728839 is an equidigital number, since it uses as much as digits as its factorization.

198728839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 55.

The square root of 198728839 is about 14097.1216565652. The cubic root of 198728839 is about 583.5619476890.

The spelling of 198728839 in words is "one hundred ninety-eight million, seven hundred twenty-eight thousand, eight hundred thirty-nine".