86807531521 has 4 divisors (see below), whose sum is σ = 86816743492. Its totient is φ = 86798319552.

The previous prime is 86807531483. The next prime is 86807531597. The reversal of 86807531521 is 12513570868.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47617786225 + 39189745296 = 218215^2 + 197964^2 .

It is a cyclic number.

It is not a de Polignac number, because 86807531521 - 2⁹ = 86807531009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (86807531021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4591836 + ... + 4610701.

It is an arithmetic number, because the mean of its divisors is an integer number (21704185873).

Almost surely, 2^86807531521 is an apocalyptic number.

It is an amenable number.

86807531521 is a deficient number, since it is larger than the sum of its proper divisors (9211971).

86807531521 is an equidigital number, since it uses as much as digits as its factorization.

86807531521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9211970.

The product of its (nonzero) digits is 403200, while the sum is 46.

The spelling of 86807531521 in words is "eighty-six billion, eight hundred seven million, five hundred thirty-one thousand, five hundred twenty-one".