66505131587 has 2 divisors, whose sum is σ = 66505131588. Its totient is φ = 66505131586.

The previous prime is 66505131569. The next prime is 66505131613. The reversal of 66505131587 is 78513150566.

66505131587 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66505131587 - 2⁸ = 66505131331 is a prime.

It is not a weakly prime, because it can be changed into another prime (66505136587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33252565793 + 33252565794.

It is an arithmetic number, because the mean of its divisors is an integer number (33252565794).

Almost surely, 2^66505131587 is an apocalyptic number.

66505131587 is a deficient number, since it is larger than the sum of its proper divisors (1).

66505131587 is an equidigital number, since it uses as much as digits as its factorization.

66505131587 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756000, while the sum is 47.

The spelling of 66505131587 in words is "sixty-six billion, five hundred five million, one hundred thirty-one thousand, five hundred eighty-seven".