8390861 has 2 divisors, whose sum is σ = 8390862. Its totient is φ = 8390860.

The previous prime is 8390857. The next prime is 8390867. The reversal of 8390861 is 1680938.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8375236 + 15625 = 2894^2 + 125^2 .

It is a cyclic number.

It is not a de Polignac number, because 8390861 - 2² = 8390857 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8390867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4195430 + 4195431.

It is an arithmetic number, because the mean of its divisors is an integer number (4195431).

Almost surely, 2^8390861 is an apocalyptic number.

It is an amenable number.

8390861 is a deficient number, since it is larger than the sum of its proper divisors (1).

8390861 is an equidigital number, since it uses as much as digits as its factorization.

8390861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 8390861 is about 2896.6982928845. The cubic root of 8390861 is about 203.2055236088.

The spelling of 8390861 in words is "eight million, three hundred ninety thousand, eight hundred sixty-one".