2121220121072 has 80 divisors (see below), whose sum is σ = 4510757959680. Its totient is φ = 960349775616.

The previous prime is 2121220121071. The next prime is 2121220121159. The reversal of 2121220121072 is 2701210221212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121220121071) 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, 5495273 + ... + 5868599.

It is an arithmetic number, because the mean of its divisors is an integer number (56384474496).

Almost surely, 2^{2121220121072} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2121220121072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2255378979840).

2121220121072 is an abundant number, since it is smaller than the sum of its proper divisors (2389537838608).

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

2121220121072 is a wasteful number, since it uses less digits than its factorization.

2121220121072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373870 (or 373864 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

Adding to 2121220121072 its reverse (2701210221212), we get a palindrome (4822430342284).

The spelling of 2121220121072 in words is "two trillion, one hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, seventy-two".