1002001021621 has 2 divisors, whose sum is σ = 1002001021622. Its totient is φ = 1002001021620.

The previous prime is 1002001021613. The next prime is 1002001021633. The reversal of 1002001021621 is 1261201002001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 769855327396 + 232145694225 = 877414^2 + 481815^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002001021621 - 2³ = 1002001021613 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1002001021595 and 1002001021604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1002001021601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 501000510810 + 501000510811.

It is an arithmetic number, because the mean of its divisors is an integer number (501000510811).

Almost surely, 2^{1002001021621} is an apocalyptic number.

It is an amenable number.

1002001021621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1002001021621 is an equidigital number, since it uses as much as digits as its factorization.

1002001021621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 1002001021621 its reverse (1261201002001), we get a palindrome (2263202023622).

The spelling of 1002001021621 in words is "one trillion, two billion, one million, twenty-one thousand, six hundred twenty-one".