2121122221220 has 24 divisors (see below), whose sum is σ = 4460802940608. Its totient is φ = 847221026400.

The previous prime is 2121122221219. The next prime is 2121122221223. The reversal of 2121122221220 is 221222211212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 2121122221192 and 2121122221201.

It is not an unprimeable number, because it can be changed into a prime (2121122221223) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 76727216 + ... + 76754855.

It is an arithmetic number, because the mean of its divisors is an integer number (185866789192).

Almost surely, 2^{2121122221220} is an apocalyptic number.

2121122221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121122221220 is an abundant number, since it is smaller than the sum of its proper divisors (2339680719388).

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

2121122221220 is a wasteful number, since it uses less digits than its factorization.

2121122221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153482771 (or 153482769 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 2121122221220 its reverse (221222211212), we get a palindrome (2342344432432).

The spelling of 2121122221220 in words is "two trillion, one hundred twenty-one billion, one hundred twenty-two million, two hundred twenty-one thousand, two hundred twenty".