666312517 has 8 divisors (see below), whose sum is σ = 717809624. Its totient is φ = 614850048.

The previous prime is 666312503. The next prime is 666312527. The reversal of 666312517 is 715213666.

It can be written as a sum of positive squares in 4 ways, for example, as 982081 + 665330436 = 991^2 + 25794^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666312517 - 2⁷ = 666312389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666312527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42553 + ... + 56065.

It is an arithmetic number, because the mean of its divisors is an integer number (89726203).

Almost surely, 2^666312517 is an apocalyptic number.

It is an amenable number.

666312517 is a deficient number, since it is larger than the sum of its proper divisors (51497107).

666312517 is a wasteful number, since it uses less digits than its factorization.

666312517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17319.

The product of its digits is 45360, while the sum is 37.

The square root of 666312517 is about 25813.0299848739. The cubic root of 666312517 is about 873.4257482215.

The spelling of 666312517 in words is "six hundred sixty-six million, three hundred twelve thousand, five hundred seventeen".