121121121221220 has 384 divisors, whose sum is σ = 355657236480000. Its totient is φ = 30763292958720.

The previous prime is 121121121221213. The next prime is 121121121221227. The reversal of 121121121221220 is 22122121121121.

It is an interprime number because it is at equal distance from previous prime (121121121221213) and next prime (121121121221227).

It is not an unprimeable number, because it can be changed into a prime (121121121221227) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 26053153456 + ... + 26053158104.

It is an arithmetic number, because the mean of its divisors is an integer number (926190720000).

Almost surely, 2^{121121121221220} is an apocalyptic number.

121121121221220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121121121221220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177828618240000).

121121121221220 is an abundant number, since it is smaller than the sum of its proper divisors (234536115258780).

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

121121121221220 is a wasteful number, since it uses less digits than its factorization.

121121121221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5603 (or 5601 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 121121121221220 its reverse (22122121121121), we get a palindrome (143243242342341).

The spelling of 121121121221220 in words is "one hundred twenty-one trillion, one hundred twenty-one billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty".