8417821 has 2 divisors, whose sum is σ = 8417822. Its totient is φ = 8417820.

The previous prime is 8417807. The next prime is 8417891. The reversal of 8417821 is 1287148.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6125625 + 2292196 = 2475^2 + 1514^2 .

It is a cyclic number.

It is not a de Polignac number, because 8417821 - 2⁷ = 8417693 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8417891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4208910 + 4208911.

It is an arithmetic number, because the mean of its divisors is an integer number (4208911).

Almost surely, 2^8417821 is an apocalyptic number.

It is an amenable number.

8417821 is a deficient number, since it is larger than the sum of its proper divisors (1).

8417821 is an equidigital number, since it uses as much as digits as its factorization.

8417821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3584, while the sum is 31.

The square root of 8417821 is about 2901.3481349194. The cubic root of 8417821 is about 203.4229253726.

The spelling of 8417821 in words is "eight million, four hundred seventeen thousand, eight hundred twenty-one".