2121222220 has 24 divisors (see below), whose sum is σ = 4797226224. Its totient is φ = 783220416.

The previous prime is 2121222193. The next prime is 2121222227. The reversal of 2121222220 is 222221212.

It is a junction number, because it is equal to n+sod(n) for n = 2121222194 and 2121222203.

It is not an unprimeable number, because it can be changed into a prime (2121222227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4079014 + ... + 4079533.

It is an arithmetic number, because the mean of its divisors is an integer number (199884426).

Almost surely, 2^2121222220 is an apocalyptic number.

2121222220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2121222220 is an abundant number, since it is smaller than the sum of its proper divisors (2676004004).

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

2121222220 is a wasteful number, since it uses less digits than its factorization.

2121222220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8158569 (or 8158567 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 2121222220 is about 46056.7282815443. The cubic root of 2121222220 is about 1284.8784817486.

Adding to 2121222220 its reverse (222221212), we get a palindrome (2343443432).

The spelling of 2121222220 in words is "two billion, one hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty".