86579821 has 2 divisors, whose sum is σ = 86579822. Its totient is φ = 86579820.

The previous prime is 86579803. The next prime is 86579849. The reversal of 86579821 is 12897568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43414921 + 43164900 = 6589^2 + 6570^2 .

It is a cyclic number.

It is not a de Polignac number, because 86579821 - 2⁷ = 86579693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86579851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43289910 + 43289911.

It is an arithmetic number, because the mean of its divisors is an integer number (43289911).

Almost surely, 2^86579821 is an apocalyptic number.

It is an amenable number.

86579821 is a deficient number, since it is larger than the sum of its proper divisors (1).

86579821 is an equidigital number, since it uses as much as digits as its factorization.

86579821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 46.

The square root of 86579821 is about 9304.8278329048. The cubic root of 86579821 is about 442.3902646379.

The spelling of 86579821 in words is "eighty-six million, five hundred seventy-nine thousand, eight hundred twenty-one".