211121212221961 has 2 divisors, whose sum is σ = 211121212221962. Its totient is φ = 211121212221960.

The previous prime is 211121212221841. The next prime is 211121212222007. The reversal of 211121212221961 is 169122212121112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186667841070736 + 24453371151225 = 13662644^2 + 4945035^2 .

It is a cyclic number.

It is not a de Polignac number, because 211121212221961 - 2⁷ = 211121212221833 is a prime.

It is not a weakly prime, because it can be changed into another prime (211121212228961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105560606110980 + 105560606110981.

It is an arithmetic number, because the mean of its divisors is an integer number (105560606110981).

Almost surely, 2^{211121212221961} is an apocalyptic number.

It is an amenable number.

211121212221961 is a deficient number, since it is larger than the sum of its proper divisors (1).

211121212221961 is an equidigital number, since it uses as much as digits as its factorization.

211121212221961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 34.

The spelling of 211121212221961 in words is "two hundred eleven trillion, one hundred twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, nine hundred sixty-one".