121220111111111 has 8 divisors (see below), whose sum is σ = 121658977262304. Its totient is φ = 120781253941920.

The previous prime is 121220111111101. The next prime is 121220111111149. The reversal of 121220111111111 is 111111111022121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121220111111111 is a prime.

It is a Duffinian number.

121220111111111 is a modest number, since divided by 11111111 gives 1212201 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 121220111111111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220111111101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25410566 + ... + 29801628.

It is an arithmetic number, because the mean of its divisors is an integer number (15207372157788).

Almost surely, 2^{121220111111111} is an apocalyptic number.

121220111111111 is a deficient number, since it is larger than the sum of its proper divisors (438866151193).

121220111111111 is an equidigital number, since it uses as much as digits as its factorization.

121220111111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4491001.

The product of its (nonzero) digits is 8, while the sum is 17.

Adding to 121220111111111 its reverse (111111111022121), we get a palindrome (232331222133232).

The spelling of 121220111111111 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, one hundred eleven thousand, one hundred eleven".