8459821 has 2 divisors, whose sum is σ = 8459822. Its totient is φ = 8459820.

The previous prime is 8459813. The next prime is 8459827. The reversal of 8459821 is 1289548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4515625 + 3944196 = 2125^2 + 1986^2 .

It is a cyclic number.

It is not a de Polignac number, because 8459821 - 2³ = 8459813 is a prime.

8459821 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8459827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4229910 + 4229911.

It is an arithmetic number, because the mean of its divisors is an integer number (4229911).

Almost surely, 2^8459821 is an apocalyptic number.

It is an amenable number.

8459821 is a deficient number, since it is larger than the sum of its proper divisors (1).

8459821 is an equidigital number, since it uses as much as digits as its factorization.

8459821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23040, while the sum is 37.

The square root of 8459821 is about 2908.5771435532. The cubic root of 8459821 is about 203.7606846994.

The spelling of 8459821 in words is "eight million, four hundred fifty-nine thousand, eight hundred twenty-one".