2001100220221 has 4 divisors (see below), whose sum is σ = 2002766416444. Its totient is φ = 1999434024000.

The previous prime is 2001100220213. The next prime is 2001100220227. The reversal of 2001100220221 is 1220220011002.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 509003768025 + 1492096452196 = 713445^2 + 1221514^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001100220221 - 2³ = 2001100220213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001100220227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 833096310 + ... + 833098711.

It is an arithmetic number, because the mean of its divisors is an integer number (500691604111).

Almost surely, 2^{2001100220221} is an apocalyptic number.

It is an amenable number.

2001100220221 is a deficient number, since it is larger than the sum of its proper divisors (1666196223).

2001100220221 is a wasteful number, since it uses less digits than its factorization.

2001100220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666196222.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 2001100220221 its reverse (1220220011002), we get a palindrome (3221320231223).

The spelling of 2001100220221 in words is "two trillion, one billion, one hundred million, two hundred twenty thousand, two hundred twenty-one".