666681736473 has 12 divisors (see below), whose sum is σ = 962998710180. Its totient is φ = 444448038816.

The previous prime is 666681736453. The next prime is 666681736537. The reversal of 666681736473 is 374637186666.

It can be written as a sum of positive squares in 2 ways, for example, as 315397929609 + 351283806864 = 561603^2 + 592692^2 .

It is not a de Polignac number, because 666681736473 - 2¹⁶ = 666681670937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666681736473.

It is not an unprimeable number, because it can be changed into a prime (666681736453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165063 + ... + 1166451.

It is an arithmetic number, because the mean of its divisors is an integer number (80249892515).

Almost surely, 2^666681736473 is an apocalyptic number.

It is an amenable number.

666681736473 is a deficient number, since it is larger than the sum of its proper divisors (296316973707).

666681736473 is a wasteful number, since it uses less digits than its factorization.

666681736473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1075368 (or 1075365 counting only the distinct ones).

The product of its digits is 109734912, while the sum is 63.

The spelling of 666681736473 in words is "six hundred sixty-six billion, six hundred eighty-one million, seven hundred thirty-six thousand, four hundred seventy-three".