2121220121020 has 192 divisors, whose sum is σ = 5982641280000. Its totient is φ = 610128599040.

The previous prime is 2121220120979. The next prime is 2121220121023. The reversal of 2121220121020 is 201210221212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 2121220120985 and 2121220121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121220121023) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 82049056 + ... + 82074904.

It is an arithmetic number, because the mean of its divisors is an integer number (31159590000).

Almost surely, 2^{2121220121020} is an apocalyptic number.

2121220121020 is a gapful number since it is divisible by the number (20) 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 2121220121020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2991320640000).

2121220121020 is an abundant number, since it is smaller than the sum of its proper divisors (3861421158980).

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

2121220121020 is a wasteful number, since it uses less digits than its factorization.

2121220121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29988 (or 29986 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2121220121020 its reverse (201210221212), we get a palindrome (2322430342232).

The spelling of 2121220121020 in words is "two trillion, one hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, twenty".