2005021 has 2 divisors, whose sum is σ = 2005022. Its totient is φ = 2005020.

The previous prime is 2005019. The next prime is 2005027. The reversal of 2005021 is 1205002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1999396 + 5625 = 1414^2 + 75^2 .

It is a cyclic number.

It is not a de Polignac number, because 2005021 - 2¹ = 2005019 is a prime.

Together with 2005019, it forms a pair of twin primes.

2005021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2004989 and 2005007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2005027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1002510 + 1002511.

It is an arithmetic number, because the mean of its divisors is an integer number (1002511).

2^2005021 is an apocalyptic number.

It is an amenable number.

2005021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2005021 is an equidigital number, since it uses as much as digits as its factorization.

2005021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 2005021 is about 1415.9876411890. The cubic root of 2005021 is about 126.0974512745.

The spelling of 2005021 in words is "two million, five thousand, twenty-one".