198818899823 has 4 divisors (see below), whose sum is σ = 204192383640. Its totient is φ = 193445416008.

The previous prime is 198818899801. The next prime is 198818899879. The reversal of 198818899823 is 328998818891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 328998818891 = 373 ⋅882034367.

It is a cyclic number.

It is not a de Polignac number, because 198818899823 - 2²⁸ = 198550464367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198818895823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2686741853 + ... + 2686741926.

It is an arithmetic number, because the mean of its divisors is an integer number (51048095910).

Almost surely, 2^198818899823 is an apocalyptic number.

198818899823 is a deficient number, since it is larger than the sum of its proper divisors (5373483817).

198818899823 is an equidigital number, since it uses as much as digits as its factorization.

198818899823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5373483816.

The product of its digits is 143327232, while the sum is 74.

The spelling of 198818899823 in words is "one hundred ninety-eight billion, eight hundred eighteen million, eight hundred ninety-nine thousand, eight hundred twenty-three".