667431517 has 4 divisors (see below), whose sum is σ = 667501660. Its totient is φ = 667361376.

The previous prime is 667431511. The next prime is 667431547. The reversal of 667431517 is 715134766.

667431517 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 472019076 + 195412441 = 21726^2 + 13979^2 .

It is a cyclic number.

It is not a de Polignac number, because 667431517 - 2⁷ = 667431389 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 667431517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667431511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18042 + ... + 40747.

It is an arithmetic number, because the mean of its divisors is an integer number (166875415).

Almost surely, 2^667431517 is an apocalyptic number.

It is an amenable number.

667431517 is a deficient number, since it is larger than the sum of its proper divisors (70143).

667431517 is a wasteful number, since it uses less digits than its factorization.

667431517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70142.

The product of its digits is 105840, while the sum is 40.

The square root of 667431517 is about 25834.6959920182. The cubic root of 667431517 is about 873.9144162122.

The spelling of 667431517 in words is "six hundred sixty-seven million, four hundred thirty-one thousand, five hundred seventeen".