666783647999 has 12 divisors (see below), whose sum is σ = 781307943984. Its totient is φ = 567357092064.

The previous prime is 666783647987. The next prime is 666783648043. The reversal of 666783647999 is 999746387666.

It is a de Polignac number, because none of the positive numbers 2^k-666783647999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666783617999) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49656899 + ... + 49670324.

It is an arithmetic number, because the mean of its divisors is an integer number (65108995332).

Almost surely, 2^666783647999 is an apocalyptic number.

666783647999 is a deficient number, since it is larger than the sum of its proper divisors (114524295985).

666783647999 is a wasteful number, since it uses less digits than its factorization.

666783647999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99327374 (or 99327367 counting only the distinct ones).

The product of its digits is 4444263936, while the sum is 80.

The spelling of 666783647999 in words is "six hundred sixty-six billion, seven hundred eighty-three million, six hundred forty-seven thousand, nine hundred ninety-nine".