8669821 has 2 divisors, whose sum is σ = 8669822. Its totient is φ = 8669820.

The previous prime is 8669777. The next prime is 8669831. The reversal of 8669821 is 1289668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6943225 + 1726596 = 2635^2 + 1314^2 .

It is a cyclic number.

It is not a de Polignac number, because 8669821 - 2¹³ = 8661629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8669831) 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, 4334910 + 4334911.

It is an arithmetic number, because the mean of its divisors is an integer number (4334911).

Almost surely, 2^8669821 is an apocalyptic number.

It is an amenable number.

8669821 is a deficient number, since it is larger than the sum of its proper divisors (1).

8669821 is an equidigital number, since it uses as much as digits as its factorization.

8669821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 40.

The square root of 8669821 is about 2944.4559769166. The cubic root of 8669821 is about 205.4329221067.

The spelling of 8669821 in words is "eight million, six hundred sixty-nine thousand, eight hundred twenty-one".