210121220212081 has 2 divisors, whose sum is σ = 210121220212082. Its totient is φ = 210121220212080.

The previous prime is 210121220212073. The next prime is 210121220212087. The reversal of 210121220212081 is 180212022121012.

210121220212081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123227427616225 + 86893792595856 = 11100785^2 + 9321684^2 .

It is a cyclic number.

It is not a de Polignac number, because 210121220212081 - 2³ = 210121220212073 is a prime.

It is a super-2 number, since 2×210121220212081² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (210121220212087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105060610106040 + 105060610106041.

It is an arithmetic number, because the mean of its divisors is an integer number (105060610106041).

Almost surely, 2^{210121220212081} is an apocalyptic number.

It is an amenable number.

210121220212081 is a deficient number, since it is larger than the sum of its proper divisors (1).

210121220212081 is an equidigital number, since it uses as much as digits as its factorization.

210121220212081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 25.

Adding to 210121220212081 its reverse (180212022121012), we get a palindrome (390333242333093).

The spelling of 210121220212081 in words is "two hundred ten trillion, one hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, eighty-one".