2001122122221 has 96 divisors (see below), whose sum is σ = 3285376174080. Its totient is φ = 1166200588800.

The previous prime is 2001122122193. The next prime is 2001122122231. The reversal of 2001122122221 is 1222212211002.

It is a happy number.

2001122122221 is a `hidden beast` number, since 200 + 1 + 1 + 221 + 22 + 221 = 666.

It is not a de Polignac number, because 2001122122221 - 2⁵ = 2001122122189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001122122194 and 2001122122203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001122122231) 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 95 ways as a sum of consecutive naturals, for example, 31576156 + ... + 31639466.

It is an arithmetic number, because the mean of its divisors is an integer number (34222668480).

Almost surely, 2^{2001122122221} is an apocalyptic number.

It is an amenable number.

2001122122221 is a deficient number, since it is larger than the sum of its proper divisors (1284254051859).

2001122122221 is a wasteful number, since it uses less digits than its factorization.

2001122122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63567 (or 63564 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 2001122122221 its reverse (1222212211002), we get a palindrome (3223334333223).

The spelling of 2001122122221 in words is "two trillion, one billion, one hundred twenty-two million, one hundred twenty-two thousand, two hundred twenty-one".