2001221022021 has 24 divisors (see below), whose sum is σ = 2988969187680. Its totient is φ = 1189054391616.

The previous prime is 2001221021977. The next prime is 2001221022023. The reversal of 2001221022021 is 1202201221002.

It is not a de Polignac number, because 2001221022021 - 2³¹ = 1999073538373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001221022023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68040151 + ... + 68069556.

It is an arithmetic number, because the mean of its divisors is an integer number (124540382820).

Almost surely, 2^{2001221022021} is an apocalyptic number.

It is an amenable number.

2001221022021 is a deficient number, since it is larger than the sum of its proper divisors (987748165659).

2001221022021 is a wasteful number, since it uses less digits than its factorization.

2001221022021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136109765 (or 136109752 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 2001221022021 its reverse (1202201221002), we get a palindrome (3203422243023).

The spelling of 2001221022021 in words is "two trillion, one billion, two hundred twenty-one million, twenty-two thousand, twenty-one".