8667821 has 2 divisors, whose sum is σ = 8667822. Its totient is φ = 8667820.

The previous prime is 8667809. The next prime is 8667829. The reversal of 8667821 is 1287668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6375625 + 2292196 = 2525^2 + 1514^2 .

It is a cyclic number.

It is not a de Polignac number, because 8667821 - 2¹⁰ = 8666797 is a prime.

It is a super-2 number, since 2×8667821² = 150262241776082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8667829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4333910 + 4333911.

It is an arithmetic number, because the mean of its divisors is an integer number (4333911).

Almost surely, 2^8667821 is an apocalyptic number.

It is an amenable number.

8667821 is a deficient number, since it is larger than the sum of its proper divisors (1).

8667821 is an equidigital number, since it uses as much as digits as its factorization.

8667821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 38.

The square root of 8667821 is about 2944.1163360166. The cubic root of 8667821 is about 205.4171241088.

The spelling of 8667821 in words is "eight million, six hundred sixty-seven thousand, eight hundred twenty-one".