2220001221 has 32 divisors (see below), whose sum is σ = 3078547200. Its totient is φ = 1421881344.

The previous prime is 2220001187. The next prime is 2220001261. The reversal of 2220001221 is 1221000222.

It is not a de Polignac number, because 2220001221 - 2⁷ = 2220001093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2220001197 and 2220001206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2220001261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3705880 + ... + 3706478.

It is an arithmetic number, because the mean of its divisors is an integer number (96204600).

Almost surely, 2^2220001221 is an apocalyptic number.

It is an amenable number.

2220001221 is a deficient number, since it is larger than the sum of its proper divisors (858545979).

2220001221 is a wasteful number, since it uses less digits than its factorization.

2220001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 2220001221 is about 47116.8889146981. Note that the first 3 decimals coincide. The cubic root of 2220001221 is about 1304.5209891825.

Adding to 2220001221 its reverse (1221000222), we get a palindrome (3441001443).

Subtracting from 2220001221 its reverse (1221000222), we obtain a palindrome (999000999).

It can be divided in two parts, 2220001 and 221, that added together give a palindrome (2220222).

The spelling of 2220001221 in words is "two billion, two hundred twenty million, one thousand, two hundred twenty-one".