2001212022221 has 4 divisors (see below), whose sum is σ = 2002572466944. Its totient is φ = 1999851577500.

The previous prime is 2001212022109. The next prime is 2001212022263. The reversal of 2001212022221 is 1222202121002.

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 2001212022221 - 2¹⁰ = 2001212021197 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2001212022221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001212024221) 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, 680220155 + ... + 680223096.

It is an arithmetic number, because the mean of its divisors is an integer number (500643116736).

Almost surely, 2^{2001212022221} is an apocalyptic number.

It is an amenable number.

2001212022221 is a deficient number, since it is larger than the sum of its proper divisors (1360444723).

2001212022221 is a wasteful number, since it uses less digits than its factorization.

2001212022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360444722.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 2001212022221 its reverse (1222202121002), we get a palindrome (3223414143223).

The spelling of 2001212022221 in words is "two trillion, one billion, two hundred twelve million, twenty-two thousand, two hundred twenty-one".