198945071809 has 4 divisors (see below), whose sum is σ = 217030987440. Its totient is φ = 180859156180.

The previous prime is 198945071797. The next prime is 198945071849. The reversal of 198945071809 is 908170549891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 198945071809 - 2¹¹ = 198945069761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198945071849) 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, 9042957799 + ... + 9042957820.

It is an arithmetic number, because the mean of its divisors is an integer number (54257746860).

Almost surely, 2^198945071809 is an apocalyptic number.

It is an amenable number.

198945071809 is a deficient number, since it is larger than the sum of its proper divisors (18085915631).

198945071809 is a wasteful number, since it uses less digits than its factorization.

198945071809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18085915630.

The product of its (nonzero) digits is 6531840, while the sum is 61.

The spelling of 198945071809 in words is "one hundred ninety-eight billion, nine hundred forty-five million, seventy-one thousand, eight hundred nine".