8684821 has 2 divisors, whose sum is σ = 8684822. Its totient is φ = 8684820.

The previous prime is 8684789. The next prime is 8684831. The reversal of 8684821 is 1284868.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4901796 + 3783025 = 2214^2 + 1945^2 .

It is a cyclic number.

It is not a de Polignac number, because 8684821 - 2⁵ = 8684789 is a prime.

It is a super-2 number, since 2×8684821² = 150852231604082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8684831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4342410 + 4342411.

It is an arithmetic number, because the mean of its divisors is an integer number (4342411).

Almost surely, 2^8684821 is an apocalyptic number.

It is an amenable number.

8684821 is a deficient number, since it is larger than the sum of its proper divisors (1).

8684821 is an equidigital number, since it uses as much as digits as its factorization.

8684821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24576, while the sum is 37.

The square root of 8684821 is about 2947.0020359681. The cubic root of 8684821 is about 205.5513297186.

The spelling of 8684821 in words is "eight million, six hundred eighty-four thousand, eight hundred twenty-one".