666730987993 has 12 divisors (see below), whose sum is σ = 777519177012. Its totient is φ = 570058540800.

The previous prime is 666730987919. The next prime is 666730987999. The reversal of 666730987993 is 399789037666.

It can be written as a sum of positive squares in 2 ways, for example, as 572637265984 + 94093722009 = 756728^2 + 306747^2 .

It is not a de Polignac number, because 666730987993 - 2²⁹ = 666194117081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666730987999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16946380 + ... + 16985677.

It is an arithmetic number, because the mean of its divisors is an integer number (64793264751).

Almost surely, 2^666730987993 is an apocalyptic number.

It is an amenable number.

666730987993 is a deficient number, since it is larger than the sum of its proper divisors (110788189019).

666730987993 is a wasteful number, since it uses less digits than its factorization.

666730987993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33932472 (or 33932465 counting only the distinct ones).

The product of its (nonzero) digits is 555532992, while the sum is 73.

The spelling of 666730987993 in words is "six hundred sixty-six billion, seven hundred thirty million, nine hundred eighty-seven thousand, nine hundred ninety-three".