2001212020021 has 8 divisors (see below), whose sum is σ = 2012259098520. Its totient is φ = 1990171932672.

The previous prime is 2001212020009. The next prime is 2001212020051. The reversal of 2001212020021 is 1200202121002.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 124777791121 + 1876434228900 = 353239^2 + 1369830^2 .

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 2001212020021 - 2⁷ = 2001212019893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001212019983 and 2001212020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001212020051) 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 7 ways as a sum of consecutive naturals, for example, 1173190 + ... + 2319223.

It is an arithmetic number, because the mean of its divisors is an integer number (251532387315).

Almost surely, 2^{2001212020021} is an apocalyptic number.

It is an amenable number.

2001212020021 is a deficient number, since it is larger than the sum of its proper divisors (11047078499).

2001212020021 is a wasteful number, since it uses less digits than its factorization.

2001212020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3495575.

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

Adding to 2001212020021 its reverse (1200202121002), we get a palindrome (3201414141023).

The spelling of 2001212020021 in words is "two trillion, one billion, two hundred twelve million, twenty thousand, twenty-one".