2001002011021 has 24 divisors (see below), whose sum is σ = 2215194926280. Its totient is φ = 1796789060352.

The previous prime is 2001002011003. The next prime is 2001002011037. The reversal of 2001002011021 is 1201102001002.

It can be written as a sum of positive squares in 12 ways, for example, as 238719210921 + 1762282800100 = 488589^2 + 1327510^2 .

It is not a de Polignac number, because 2001002011021 - 2¹³ = 2001002002829 is a prime.

It is a super-2 number, since 2×2001002011021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001002010989 and 2001002011007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001002011621) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 124517575 + ... + 124533643.

It is an arithmetic number, because the mean of its divisors is an integer number (92299788595).

Almost surely, 2^{2001002011021} is an apocalyptic number.

It is an amenable number.

2001002011021 is a deficient number, since it is larger than the sum of its proper divisors (214192915259).

2001002011021 is a wasteful number, since it uses less digits than its factorization.

2001002011021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23153 (or 23116 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 2001002011021 its reverse (1201102001002), we get a palindrome (3202104012023).

The spelling of 2001002011021 in words is "two trillion, one billion, two million, eleven thousand, twenty-one".