667665017 has 4 divisors (see below), whose sum is σ = 671353956. Its totient is φ = 663976080.

The previous prime is 667664989. The next prime is 667665023. The reversal of 667665017 is 710566766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 155276521 + 512388496 = 12461^2 + 22636^2 .

It is a cyclic number.

It is not a de Polignac number, because 667665017 - 2¹⁶ = 667599481 is a prime.

It is a super-2 number, since 2×667665017² = 891553149851220578, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667665067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1844198 + ... + 1844559.

It is an arithmetic number, because the mean of its divisors is an integer number (167838489).

Almost surely, 2^667665017 is an apocalyptic number.

It is an amenable number.

667665017 is a deficient number, since it is larger than the sum of its proper divisors (3688939).

667665017 is a wasteful number, since it uses less digits than its factorization.

667665017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3688938.

The product of its (nonzero) digits is 317520, while the sum is 44.

The square root of 667665017 is about 25839.2147132996. The cubic root of 667665017 is about 874.0163169161.

The spelling of 667665017 in words is "six hundred sixty-seven million, six hundred sixty-five thousand, seventeen".