666597 has 4 divisors (see below), whose sum is σ = 888800. Its totient is φ = 444396.

The previous prime is 666559. The next prime is 666599. The reversal of 666597 is 795666.

It is a happy number.

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 not a de Polignac number, because 666597 - 2¹⁰ = 665573 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 666597.

It is not an unprimeable number, because it can be changed into a prime (666599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111097 + ... + 111102.

It is an arithmetic number, because the mean of its divisors is an integer number (222200).

2⁶⁶⁶⁵⁹⁷ is an apocalyptic number.

It is an amenable number.

666597 is a deficient number, since it is larger than the sum of its proper divisors (222203).

666597 is a wasteful number, since it uses less digits than its factorization.

666597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222202.

The product of its digits is 68040, while the sum is 39.

The square root of 666597 is about 816.4539178668. The cubic root of 666597 is about 87.3550033957.

It can be divided in two parts, 66659 and 7, that added together give a palindrome (66666).

The spelling of 666597 in words is "six hundred sixty-six thousand, five hundred ninety-seven".