86784521 has 2 divisors, whose sum is σ = 86784522. Its totient is φ = 86784520.

The previous prime is 86784493. The next prime is 86784539. The reversal of 86784521 is 12548768.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83978896 + 2805625 = 9164^2 + 1675^2 .

It is a cyclic number.

It is not a de Polignac number, because 86784521 - 2¹⁰ = 86783497 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (86784121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43392260 + 43392261.

It is an arithmetic number, because the mean of its divisors is an integer number (43392261).

Almost surely, 2^86784521 is an apocalyptic number.

It is an amenable number.

86784521 is a deficient number, since it is larger than the sum of its proper divisors (1).

86784521 is an equidigital number, since it uses as much as digits as its factorization.

86784521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 107520, while the sum is 41.

The square root of 86784521 is about 9315.8210051503. The cubic root of 86784521 is about 442.7386368558.

The spelling of 86784521 in words is "eighty-six million, seven hundred eighty-four thousand, five hundred twenty-one".