9000821 has 2 divisors, whose sum is σ = 9000822. Its totient is φ = 9000820.

The previous prime is 9000809. The next prime is 9000839. The reversal of 9000821 is 1280009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8059921 + 940900 = 2839^2 + 970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9000821 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 9000793 and 9000802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9000841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4500410 + 4500411.

It is an arithmetic number, because the mean of its divisors is an integer number (4500411).

Almost surely, 2^9000821 is an apocalyptic number.

It is an amenable number.

9000821 is a deficient number, since it is larger than the sum of its proper divisors (1).

9000821 is an equidigital number, since it uses as much as digits as its factorization.

9000821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 9000821 is about 3000.1368302129. The cubic root of 9000821 is about 208.0147071085.

The spelling of 9000821 in words is "nine million, eight hundred twenty-one", and thus it is an aban number.