2001115021 has 2 divisors, whose sum is σ = 2001115022. Its totient is φ = 2001115020.

The previous prime is 2001115019. The next prime is 2001115031. The reversal of 2001115021 is 1205111002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1928439396 + 72675625 = 43914^2 + 8525^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001115021 - 2¹ = 2001115019 is a prime.

It is a super-2 number, since 2×2001115021² = 8008922654543660882, which contains 22 as substring.

Together with 2001115019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2001114992 and 2001115010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001115031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000557510 + 1000557511.

It is an arithmetic number, because the mean of its divisors is an integer number (1000557511).

Almost surely, 2^2001115021 is an apocalyptic number.

It is an amenable number.

2001115021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001115021 is an equidigital number, since it uses as much as digits as its factorization.

2001115021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20, while the sum is 13.

The square root of 2001115021 is about 44733.8241267165. The cubic root of 2001115021 is about 1260.1551461347.

Adding to 2001115021 its reverse (1205111002), we get a palindrome (3206226023).

The spelling of 2001115021 in words is "two billion, one million, one hundred fifteen thousand, twenty-one".