121221021111111 has 12 divisors (see below), whose sum is σ = 175097127922080. Its totient is φ = 80813969107200.

The previous prime is 121221021111031. The next prime is 121221021111149. The reversal of 121221021111111 is 111111120122121.

121221021111111 is a `hidden beast` number, since 1 + 212 + 210 + 21 + 111 + 111 = 666.

It is not a de Polignac number, because 121221021111111 - 2⁷ = 121221021110983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221021111161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24661570 + ... + 29165648.

It is an arithmetic number, because the mean of its divisors is an integer number (14591427326840).

Almost surely, 2^{121221021111111} is an apocalyptic number.

121221021111111 is a deficient number, since it is larger than the sum of its proper divisors (53876106810969).

121221021111111 is a wasteful number, since it uses less digits than its factorization.

121221021111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7494486 (or 7494483 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 18.

Adding to 121221021111111 its reverse (111111120122121), we get a palindrome (232332141233232).

The spelling of 121221021111111 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, twenty-one million, one hundred eleven thousand, one hundred eleven".