2002121221 has 4 divisors (see below), whose sum is σ = 2007114444. Its totient is φ = 1997128000.

The previous prime is 2002121207. The next prime is 2002121243. The reversal of 2002121221 is 1221212002.

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 1608892321 + 393228900 = 40111^2 + 19830^2 .

It is a cyclic number.

It is not a de Polignac number, because 2002121221 - 2²¹ = 2000024069 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 (2002121021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2496010 + ... + 2496811.

It is an arithmetic number, because the mean of its divisors is an integer number (501778611).

Almost surely, 2^2002121221 is an apocalyptic number.

It is an amenable number.

2002121221 is a deficient number, since it is larger than the sum of its proper divisors (4993223).

2002121221 is an equidigital number, since it uses as much as digits as its factorization.

2002121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4993222.

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

The square root of 2002121221 is about 44745.0692367327. The cubic root of 2002121221 is about 1260.3663210104.

Adding to 2002121221 its reverse (1221212002), we get a palindrome (3223333223).

The spelling of 2002121221 in words is "two billion, two million, one hundred twenty-one thousand, two hundred twenty-one".