198442688779 has 6 divisors (see below), whose sum is σ = 209436743940. Its totient is φ = 187998336396.

The previous prime is 198442688713. The next prime is 198442688783. The reversal of 198442688779 is 977886244891.

It is a de Polignac number, because none of the positive numbers 2^k-198442688779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198442688179) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 274851009 + ... + 274851730.

It is an arithmetic number, because the mean of its divisors is an integer number (34906123990).

Almost surely, 2^198442688779 is an apocalyptic number.

198442688779 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

198442688779 is a deficient number, since it is larger than the sum of its proper divisors (10994055161).

198442688779 is an equidigital number, since it uses as much as digits as its factorization.

198442688779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549702777 (or 549702758 counting only the distinct ones).

The product of its digits is 390168576, while the sum is 73.

The spelling of 198442688779 in words is "one hundred ninety-eight billion, four hundred forty-two million, six hundred eighty-eight thousand, seven hundred seventy-nine".