2001221112221 has 8 divisors (see below), whose sum is σ = 2108796742080. Its totient is φ = 1893870302688.

The previous prime is 2001221112199. The next prime is 2001221112223. The reversal of 2001221112221 is 1222111221002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-2001221112221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2001221112221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001221112223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56186801 + ... + 56222406.

It is an arithmetic number, because the mean of its divisors is an integer number (263599592760).

Almost surely, 2^{2001221112221} is an apocalyptic number.

It is an amenable number.

2001221112221 is a deficient number, since it is larger than the sum of its proper divisors (107575629859).

2001221112221 is a wasteful number, since it uses less digits than its factorization.

2001221112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112410163.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2001221112221 its reverse (1222111221002), we get a palindrome (3223332333223).

The spelling of 2001221112221 in words is "two trillion, one billion, two hundred twenty-one million, one hundred twelve thousand, two hundred twenty-one".