2002100001221 has 4 divisors (see below), whose sum is σ = 2013672833772. Its totient is φ = 1990527168672.

The previous prime is 2002100001203. The next prime is 2002100001259. The reversal of 2002100001221 is 1221000012002.

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 1195895344900 + 806204656321 = 1093570^2 + 897889^2 .

It is a cyclic number.

It is not a de Polignac number, because 2002100001221 - 2⁶ = 2002100001157 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 (2002100001521) 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, 5786416016 + ... + 5786416361.

It is an arithmetic number, because the mean of its divisors is an integer number (503418208443).

Almost surely, 2^{2002100001221} is an apocalyptic number.

It is an amenable number.

2002100001221 is a deficient number, since it is larger than the sum of its proper divisors (11572832551).

2002100001221 is a wasteful number, since it uses less digits than its factorization.

2002100001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11572832550.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 2002100001221 its reverse (1221000012002), we get a palindrome (3223100013223).

The spelling of 2002100001221 in words is "two trillion, two billion, one hundred million, one thousand, two hundred twenty-one".