2001002821 has 2 divisors, whose sum is σ = 2001002822. Its totient is φ = 2001002820.

The previous prime is 2001002819. The next prime is 2001002891. The reversal of 2001002821 is 1282001002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1961249796 + 39753025 = 44286^2 + 6305^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001002821 - 2¹ = 2001002819 is a prime.

Together with 2001002819, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2001002795 and 2001002804.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001002891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000501410 + 1000501411.

It is an arithmetic number, because the mean of its divisors is an integer number (1000501411).

Almost surely, 2^2001002821 is an apocalyptic number.

It is an amenable number.

2001002821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001002821 is an equidigital number, since it uses as much as digits as its factorization.

2001002821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 2001002821 is about 44732.5700245358. The cubic root of 2001002821 is about 1260.1315939237.

Adding to 2001002821 its reverse (1282001002), we get a palindrome (3283003823).

The spelling of 2001002821 in words is "two billion, one million, two thousand, eight hundred twenty-one".