667486646521 has 4 divisors (see below), whose sum is σ = 681688490112. Its totient is φ = 653284802932.

The previous prime is 667486646513. The next prime is 667486646611. The reversal of 667486646521 is 125646684766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 667486646521 - 2³ = 667486646513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 667486646521.

It is not an unprimeable number, because it can be changed into a prime (667486646821) 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 3 ways as a sum of consecutive naturals, for example, 7100921725 + ... + 7100921818.

It is an arithmetic number, because the mean of its divisors is an integer number (170422122528).

Almost surely, 2^667486646521 is an apocalyptic number.

It is an amenable number.

667486646521 is a deficient number, since it is larger than the sum of its proper divisors (14201843591).

667486646521 is a wasteful number, since it uses less digits than its factorization.

667486646521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14201843590.

The product of its digits is 69672960, while the sum is 61.

The spelling of 667486646521 in words is "six hundred sixty-seven billion, four hundred eighty-six million, six hundred forty-six thousand, five hundred twenty-one".