199990121100001 has 2 divisors, whose sum is σ = 199990121100002. Its totient is φ = 199990121100000.

The previous prime is 199990121099957. The next prime is 199990121100043. The reversal of 199990121100001 is 100001121099991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198769140299601 + 1220980800400 = 14098551^2 + 1104980^2 .

It is an emirp because it is prime and its reverse (100001121099991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199990121100001 - 2³⁵ = 199955761361633 is a prime.

It is not a weakly prime, because it can be changed into another prime (199990121100901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99995060550000 + 99995060550001.

It is an arithmetic number, because the mean of its divisors is an integer number (99995060550001).

Almost surely, 2^{199990121100001} is an apocalyptic number.

It is an amenable number.

199990121100001 is a deficient number, since it is larger than the sum of its proper divisors (1).

199990121100001 is an equidigital number, since it uses as much as digits as its factorization.

199990121100001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13122, while the sum is 43.

Adding to 199990121100001 its reverse (100001121099991), we get a palindrome (299991242199992).

The spelling of 199990121100001 in words is "one hundred ninety-nine trillion, nine hundred ninety billion, one hundred twenty-one million, one hundred thousand, one".