198450974583821 has 2 divisors, whose sum is σ = 198450974583822. Its totient is φ = 198450974583820.

The previous prime is 198450974583817. The next prime is 198450974583929. The reversal of 198450974583821 is 128385479054891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 160783160800900 + 37667813782921 = 12680030^2 + 6137411^2 .

It is an emirp because it is prime and its reverse (128385479054891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198450974583821 - 2² = 198450974583817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198450974582821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99225487291910 + 99225487291911.

It is an arithmetic number, because the mean of its divisors is an integer number (99225487291911).

Almost surely, 2^{198450974583821} is an apocalyptic number.

It is an amenable number.

198450974583821 is a deficient number, since it is larger than the sum of its proper divisors (1).

198450974583821 is an equidigital number, since it uses as much as digits as its factorization.

198450974583821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 696729600, while the sum is 74.

The spelling of 198450974583821 in words is "one hundred ninety-eight trillion, four hundred fifty billion, nine hundred seventy-four million, five hundred eighty-three thousand, eight hundred twenty-one".