20002001020021 has 4 divisors (see below), whose sum is σ = 20003030531500. Its totient is φ = 20000971508544.

The previous prime is 20002001020013. The next prime is 20002001020063. The reversal of 20002001020021 is 12002010020002.

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 3097198732996 + 16904802287025 = 1759886^2 + 4111545^2 .

It is a cyclic number.

It is not a de Polignac number, because 20002001020021 - 2³ = 20002001020013 is a prime.

It is a super-2 number, since 2×20002001020021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20002001020081) 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, 514726596 + ... + 514765453.

It is an arithmetic number, because the mean of its divisors is an integer number (5000757632875).

Almost surely, 2^{20002001020021} is an apocalyptic number.

It is an amenable number.

20002001020021 is a deficient number, since it is larger than the sum of its proper divisors (1029511479).

20002001020021 is a wasteful number, since it uses less digits than its factorization.

20002001020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1029511478.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 20002001020021 its reverse (12002010020002), we get a palindrome (32004011040023).

The spelling of 20002001020021 in words is "twenty trillion, two billion, one million, twenty thousand, twenty-one".