9020821 has 2 divisors, whose sum is σ = 9020822. Its totient is φ = 9020820.

The previous prime is 9020819. The next prime is 9020831. The reversal of 9020821 is 1280209.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7672900 + 1347921 = 2770^2 + 1161^2 .

It is a cyclic number.

It is not a de Polignac number, because 9020821 - 2¹ = 9020819 is a prime.

Together with 9020819, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 9020792 and 9020801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9020831) 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, 4510410 + 4510411.

It is an arithmetic number, because the mean of its divisors is an integer number (4510411).

Almost surely, 2^9020821 is an apocalyptic number.

It is an amenable number.

9020821 is a deficient number, since it is larger than the sum of its proper divisors (1).

9020821 is an equidigital number, since it uses as much as digits as its factorization.

9020821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 9020821 is about 3003.4681619754. The cubic root of 9020821 is about 208.1686640465.

The spelling of 9020821 in words is "nine million, twenty thousand, eight hundred twenty-one".