2121012012181 has 2 divisors, whose sum is σ = 2121012012182. Its totient is φ = 2121012012180.

The previous prime is 2121012012139. The next prime is 2121012012209. The reversal of 2121012012181 is 1812102101212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2120314576900 + 697435281 = 1456130^2 + 26409^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121012012181 - 2⁹ = 2121012011669 is a prime.

It is a super-2 number, since 2×2121012012181² (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 (2121012012481) 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, 1060506006090 + 1060506006091.

It is an arithmetic number, because the mean of its divisors is an integer number (1060506006091).

Almost surely, 2^{2121012012181} is an apocalyptic number.

It is an amenable number.

2121012012181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121012012181 is an equidigital number, since it uses as much as digits as its factorization.

2121012012181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 22.

Adding to 2121012012181 its reverse (1812102101212), we get a palindrome (3933114113393).

The spelling of 2121012012181 in words is "two trillion, one hundred twenty-one billion, twelve million, twelve thousand, one hundred eighty-one".