86856521 has 2 divisors, whose sum is σ = 86856522. Its totient is φ = 86856520.

The previous prime is 86856481. The next prime is 86856527. The reversal of 86856521 is 12565868.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77246521 + 9610000 = 8789^2 + 3100^2 .

It is a cyclic number.

It is not a de Polignac number, because 86856521 - 2⁶ = 86856457 is a prime.

It is not a weakly prime, because it can be changed into another prime (86856527) 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, 43428260 + 43428261.

It is an arithmetic number, because the mean of its divisors is an integer number (43428261).

Almost surely, 2^86856521 is an apocalyptic number.

It is an amenable number.

86856521 is a deficient number, since it is larger than the sum of its proper divisors (1).

86856521 is an equidigital number, since it uses as much as digits as its factorization.

86856521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 115200, while the sum is 41.

The square root of 86856521 is about 9319.6845976675. The cubic root of 86856521 is about 442.8610410588.

The spelling of 86856521 in words is "eighty-six million, eight hundred fifty-six thousand, five hundred twenty-one".