121221201111 has 16 divisors (see below), whose sum is σ = 164401747200. Its totient is φ = 79427961728.

The previous prime is 121221201107. The next prime is 121221201119. The reversal of 121221201111 is 111102122121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 121221201111 - 2² = 121221201107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221201119) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 818230 + ... + 954956.

It is an arithmetic number, because the mean of its divisors is an integer number (10275109200).

Almost surely, 2^121221201111 is an apocalyptic number.

121221201111 is a deficient number, since it is larger than the sum of its proper divisors (43180546089).

121221201111 is a wasteful number, since it uses less digits than its factorization.

121221201111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141798.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 121221201111 its reverse (111102122121), we get a palindrome (232323323232).

The spelling of 121221201111 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred one thousand, one hundred eleven".