200121220211981 has 2 divisors, whose sum is σ = 200121220211982. Its totient is φ = 200121220211980.

The previous prime is 200121220211929. The next prime is 200121220211993. The reversal of 200121220211981 is 189112022121002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198387084150025 + 1734136061956 = 14084995^2 + 1316866^2 .

It is a cyclic number.

It is not a de Polignac number, because 200121220211981 - 2¹⁴ = 200121220195597 is a prime.

It is a super-2 number, since 2×200121220211981² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (200121220211281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100060610105990 + 100060610105991.

It is an arithmetic number, because the mean of its divisors is an integer number (100060610105991).

Almost surely, 2^{200121220211981} is an apocalyptic number.

It is an amenable number.

200121220211981 is a deficient number, since it is larger than the sum of its proper divisors (1).

200121220211981 is an equidigital number, since it uses as much as digits as its factorization.

200121220211981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 32.

Adding to 200121220211981 its reverse (189112022121002), we get a palindrome (389233242332983).

The spelling of 200121220211981 in words is "two hundred trillion, one hundred twenty-one billion, two hundred twenty million, two hundred eleven thousand, nine hundred eighty-one".