121211212012221 has 16 divisors (see below), whose sum is σ = 166031270709824. Its totient is φ = 78600586356864.

The previous prime is 121211212012183. The next prime is 121211212012273. The reversal of 121211212012221 is 122210212112121.

It is not a de Polignac number, because 121211212012221 - 2⁶ = 121211212012157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121211212012021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 158662471 + ... + 159424596.

It is an arithmetic number, because the mean of its divisors is an integer number (10376954419364).

Almost surely, 2^{121211212012221} is an apocalyptic number.

It is an amenable number.

121211212012221 is a deficient number, since it is larger than the sum of its proper divisors (44820058697603).

121211212012221 is a wasteful number, since it uses less digits than its factorization.

121211212012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318090540.

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 121211212012221 its reverse (122210212112121), we get a palindrome (243421424124342).

The spelling of 121211212012221 in words is "one hundred twenty-one trillion, two hundred eleven billion, two hundred twelve million, twelve thousand, two hundred twenty-one".