2001212221 has 8 divisors (see below), whose sum is σ = 2198128320. Its totient is φ = 1813455072.

The previous prime is 2001212203. The next prime is 2001212233. The reversal of 2001212221 is 1222121002.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2001212221 - 2⁷ = 2001212093 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 (2001212021) 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, 2289280 + ... + 2290153.

It is an arithmetic number, because the mean of its divisors is an integer number (274766040).

Almost surely, 2^2001212221 is an apocalyptic number.

It is an amenable number.

2001212221 is a deficient number, since it is larger than the sum of its proper divisors (196916099).

2001212221 is a wasteful number, since it uses less digits than its factorization.

2001212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4579475.

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

The square root of 2001212221 is about 44734.9105397563. The cubic root of 2001212221 is about 1260.1755489428.

Adding to 2001212221 its reverse (1222121002), we get a palindrome (3223333223).

The spelling of 2001212221 in words is "two billion, one million, two hundred twelve thousand, two hundred twenty-one".