2001221102221 has 4 divisors (see below), whose sum is σ = 2183150293344. Its totient is φ = 1819291911100.

The previous prime is 2001221102159. The next prime is 2001221102297. The reversal of 2001221102221 is 1222011221002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2001221102221 - 2³¹ = 1999073618573 is a prime.

It is a super-2 number, since 2×2001221102221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001221102195 and 2001221102204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001221102921) 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, 90964595545 + ... + 90964595566.

It is an arithmetic number, because the mean of its divisors is an integer number (545787573336).

Almost surely, 2^{2001221102221} is an apocalyptic number.

It is an amenable number.

2001221102221 is a deficient number, since it is larger than the sum of its proper divisors (181929191123).

2001221102221 is a wasteful number, since it uses less digits than its factorization.

2001221102221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181929191122.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2001221102221 its reverse (1222011221002), we get a palindrome (3223232323223).

The spelling of 2001221102221 in words is "two trillion, one billion, two hundred twenty-one million, one hundred two thousand, two hundred twenty-one".