121221220111 has 2 divisors, whose sum is σ = 121221220112. Its totient is φ = 121221220110.

The previous prime is 121221220091. The next prime is 121221220147. The reversal of 121221220111 is 111022122121.

It is a weak prime.

It is an emirp because it is prime and its reverse (111022122121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121221220111 - 2¹⁹ = 121220695823 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121221220411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610610055 + 60610610056.

It is an arithmetic number, because the mean of its divisors is an integer number (60610610056).

Almost surely, 2^121221220111 is an apocalyptic number.

121221220111 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221220111 is an equidigital number, since it uses as much as digits as its factorization.

121221220111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 121221220111 its reverse (111022122121), we get a palindrome (232243342232).

The spelling of 121221220111 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, one hundred eleven".