198747779 has 2 divisors, whose sum is σ = 198747780. Its totient is φ = 198747778.

The previous prime is 198747737. The next prime is 198747793. The reversal of 198747779 is 977747891.

198747779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (977747891) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198747779 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (198747709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99373889 + 99373890.

It is an arithmetic number, because the mean of its divisors is an integer number (99373890).

Almost surely, 2^198747779 is an apocalyptic number.

198747779 is a deficient number, since it is larger than the sum of its proper divisors (1).

198747779 is an equidigital number, since it uses as much as digits as its factorization.

198747779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6223392, while the sum is 59.

The square root of 198747779 is about 14097.7934088991. The cubic root of 198747779 is about 583.5804860354.

The spelling of 198747779 in words is "one hundred ninety-eight million, seven hundred forty-seven thousand, seven hundred seventy-nine".