2001002000021 has 2 divisors, whose sum is σ = 2001002000022. Its totient is φ = 2001002000020.

The previous prime is 2001002000009. The next prime is 2001002000027. The reversal of 2001002000021 is 1200002001002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1186441599121 + 814560400900 = 1089239^2 + 902530^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001002000021 - 2⁶ = 2001001999957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001001999972 and 2001002000008.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001002000027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000501000010 + 1000501000011.

It is an arithmetic number, because the mean of its divisors is an integer number (1000501000011).

Almost surely, 2^{2001002000021} is an apocalyptic number.

It is an amenable number.

2001002000021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001002000021 is an equidigital number, since it uses as much as digits as its factorization.

2001002000021 is an odious number, because the sum of its binary digits is odd.

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

Adding to 2001002000021 its reverse (1200002001002), we get a palindrome (3201004001023).

The spelling of 2001002000021 in words is "two trillion, one billion, two million, twenty-one", and thus it is an aban number and an uban number.