198603891221 has 2 divisors, whose sum is σ = 198603891222. Its totient is φ = 198603891220.

The previous prime is 198603891217. The next prime is 198603891251. The reversal of 198603891221 is 122198306891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147697250596 + 50906640625 = 384314^2 + 225625^2 .

It is a cyclic number.

It is not a de Polignac number, because 198603891221 - 2² = 198603891217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 198603891221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198603891251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99301945610 + 99301945611.

It is an arithmetic number, because the mean of its divisors is an integer number (99301945611).

Almost surely, 2^198603891221 is an apocalyptic number.

It is an amenable number.

198603891221 is a deficient number, since it is larger than the sum of its proper divisors (1).

198603891221 is an equidigital number, since it uses as much as digits as its factorization.

198603891221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 373248, while the sum is 50.

The spelling of 198603891221 in words is "one hundred ninety-eight billion, six hundred three million, eight hundred ninety-one thousand, two hundred twenty-one".