666530889787 has 4 divisors (see below), whose sum is σ = 761749588336. Its totient is φ = 571312191240.

The previous prime is 666530889779. The next prime is 666530889799. The reversal of 666530889787 is 787988035666.

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

It is not a de Polignac number, because 666530889787 - 2³ = 666530889779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666530889757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47609349264 + ... + 47609349277.

It is an arithmetic number, because the mean of its divisors is an integer number (190437397084).

Almost surely, 2^666530889787 is an apocalyptic number.

666530889787 is a deficient number, since it is larger than the sum of its proper divisors (95218698549).

666530889787 is an equidigital number, since it uses as much as digits as its factorization.

666530889787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95218698548.

The product of its (nonzero) digits is 731566080, while the sum is 73.

The spelling of 666530889787 in words is "six hundred sixty-six billion, five hundred thirty million, eight hundred eighty-nine thousand, seven hundred eighty-seven".