2001220221 has 192 divisors, whose sum is σ = 3912523776. Its totient is φ = 892684800.

The previous prime is 2001220211. The next prime is 2001220261. The reversal of 2001220221 is 1220221002.

It is not a de Polignac number, because 2001220221 - 2⁹ = 2001219709 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2001220197 and 2001220206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001220211) 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 191 ways as a sum of consecutive naturals, for example, 24111046 + ... + 24111128.

It is an arithmetic number, because the mean of its divisors is an integer number (20377728).

Almost surely, 2^2001220221 is an apocalyptic number.

2001220221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2001220221 is a deficient number, since it is larger than the sum of its proper divisors (1911303555).

2001220221 is a wasteful number, since it uses less digits than its factorization.

2001220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192 (or 185 counting only the distinct ones).

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

The square root of 2001220221 is about 44734.9999552923. Note that the first 4 decimals coincide. The cubic root of 2001220221 is about 1260.1772281568.

Adding to 2001220221 its reverse (1220221002), we get a palindrome (3221441223).

It can be divided in two parts, 2001 and 220221, that added together give a palindrome (222222).

The spelling of 2001220221 in words is "two billion, one million, two hundred twenty thousand, two hundred twenty-one".