2121021021220 has 12 divisors (see below), whose sum is σ = 4454144144604. Its totient is φ = 848408408480.

The previous prime is 2121021021209. The next prime is 2121021021227. The reversal of 2121021021220 is 221201201212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 251506262016 + 1869514759204 = 501504^2 + 1367302^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2121021021194 and 2121021021203.

It is not an unprimeable number, because it can be changed into a prime (2121021021227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53025525511 + ... + 53025525550.

It is an arithmetic number, because the mean of its divisors is an integer number (371178678717).

Almost surely, 2^{2121021021220} is an apocalyptic number.

2121021021220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121021021220 is an abundant number, since it is smaller than the sum of its proper divisors (2333123123384).

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

2121021021220 is a wasteful number, since it uses less digits than its factorization.

2121021021220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106051051070 (or 106051051068 counting only the distinct ones).

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

Adding to 2121021021220 its reverse (221201201212), we get a palindrome (2342222222432).

The spelling of 2121021021220 in words is "two trillion, one hundred twenty-one billion, twenty-one million, twenty-one thousand, two hundred twenty".