198958304921 has 2 divisors, whose sum is σ = 198958304922. Its totient is φ = 198958304920.

The previous prime is 198958304911. The next prime is 198958304959. The reversal of 198958304921 is 129403859891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134512897600 + 64445407321 = 366760^2 + 253861^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198958304921 is a prime.

It is a super-2 number, since 2×198958304921² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (198958304911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99479152460 + 99479152461.

It is an arithmetic number, because the mean of its divisors is an integer number (99479152461).

Almost surely, 2^198958304921 is an apocalyptic number.

It is an amenable number.

198958304921 is a deficient number, since it is larger than the sum of its proper divisors (1).

198958304921 is an equidigital number, since it uses as much as digits as its factorization.

198958304921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5598720, while the sum is 59.

The spelling of 198958304921 in words is "one hundred ninety-eight billion, nine hundred fifty-eight million, three hundred four thousand, nine hundred twenty-one".