121111121220 has 48 divisors (see below), whose sum is σ = 342607147008. Its totient is φ = 31963345920.

The previous prime is 121111121213. The next prime is 121111121273. The reversal of 121111121220 is 22121111121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 121111121220.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10398916 + ... + 10410555.

It is an arithmetic number, because the mean of its divisors is an integer number (7137648896).

Almost surely, 2^121111121220 is an apocalyptic number.

121111121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121111121220 is an abundant number, since it is smaller than the sum of its proper divisors (221496025788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121111121220 is a wasteful number, since it uses less digits than its factorization.

121111121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20809580 (or 20809578 counting only the distinct ones).

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

Adding to 121111121220 its reverse (22121111121), we get a palindrome (143232232341).

The spelling of 121111121220 in words is "one hundred twenty-one billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twenty".