1005001021 has 2 divisors, whose sum is σ = 1005001022. Its totient is φ = 1005001020.

The previous prime is 1005001009. The next prime is 1005001027. The reversal of 1005001021 is 1201005001.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 614345796 + 390655225 = 24786^2 + 19765^2 .

It is a cyclic number.

It is not a de Polignac number, because 1005001021 - 2⁵ = 1005000989 is a prime.

It is a super-2 number, since 2×1005001021² = 2020054104422084882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1005000989 and 1005001007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1005001027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502500510 + 502500511.

It is an arithmetic number, because the mean of its divisors is an integer number (502500511).

Almost surely, 2^1005001021 is an apocalyptic number.

It is an amenable number.

1005001021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1005001021 is an equidigital number, since it uses as much as digits as its factorization.

1005001021 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1005001021 is about 31701.7510715102. The cubic root of 1005001021 is about 1001.6642357828.

Adding to 1005001021 its reverse (1201005001), we get a palindrome (2206006022).

The spelling of 1005001021 in words is "one billion, five million, one thousand, twenty-one".