2121220122181 has 2 divisors, whose sum is σ = 2121220122182. Its totient is φ = 2121220122180.

The previous prime is 2121220122167. The next prime is 2121220122187. The reversal of 2121220122181 is 1812210221212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1608435234081 + 512784888100 = 1268241^2 + 716090^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121220122181 - 2⁵ = 2121220122149 is a prime.

It is a super-2 number, since 2×2121220122181² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121220122187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060610061090 + 1060610061091.

It is an arithmetic number, because the mean of its divisors is an integer number (1060610061091).

Almost surely, 2^{2121220122181} is an apocalyptic number.

It is an amenable number.

2121220122181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121220122181 is an equidigital number, since it uses as much as digits as its factorization.

2121220122181 is an odious number, because the sum of its binary digits is odd.

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

Adding to 2121220122181 its reverse (1812210221212), we get a palindrome (3933430343393).

The spelling of 2121220122181 in words is "two trillion, one hundred twenty-one billion, two hundred twenty million, one hundred twenty-two thousand, one hundred eighty-one".