667884726657 has 6 divisors (see below), whose sum is σ = 964722382962. Its totient is φ = 445256484432.

The previous prime is 667884726653. The next prime is 667884726679. The reversal of 667884726657 is 756627488766.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 522742014081 + 145142712576 = 723009^2 + 380976^2 .

It is not a de Polignac number, because 667884726657 - 2² = 667884726653 is a prime.

It is not an unprimeable number, because it can be changed into a prime (667884726653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37104707028 + ... + 37104707045.

It is an arithmetic number, because the mean of its divisors is an integer number (160787063827).

Almost surely, 2^667884726657 is an apocalyptic number.

It is an amenable number.

667884726657 is a deficient number, since it is larger than the sum of its proper divisors (296837656305).

667884726657 is a wasteful number, since it uses less digits than its factorization.

667884726657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74209414079 (or 74209414076 counting only the distinct ones).

The product of its digits is 1137991680, while the sum is 72.

The spelling of 667884726657 in words is "six hundred sixty-seven billion, eight hundred eighty-four million, seven hundred twenty-six thousand, six hundred fifty-seven".