2121121021220 has 96 divisors (see below), whose sum is σ = 4684050201600. Its totient is φ = 805742106624.

The previous prime is 2121121021199. The next prime is 2121121021241. The reversal of 2121121021220 is 221201211212.

It is an interprime number because it is at equal distance from previous prime (2121121021199) and next prime (2121121021241).

It is a super-2 number, since 2×2121121021220² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11962652 + ... + 12138668.

It is an arithmetic number, because the mean of its divisors is an integer number (48792189600).

Almost surely, 2^{2121121021220} is an apocalyptic number.

2121121021220 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 2121121021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2342025100800).

2121121021220 is an abundant number, since it is smaller than the sum of its proper divisors (2562929180380).

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

2121121021220 is a wasteful number, since it uses less digits than its factorization.

2121121021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176397 (or 176395 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2121121021220 its reverse (221201211212), we get a palindrome (2342322232432).

The spelling of 2121121021220 in words is "two trillion, one hundred twenty-one billion, one hundred twenty-one million, twenty-one thousand, two hundred twenty".