666595 has 4 divisors (see below), whose sum is σ = 799920. Its totient is φ = 533272.

The previous prime is 666559. The next prime is 666599. The reversal of 666595 is 595666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 595666 = 2 ⋅297833.

It is a cyclic number.

It is not a de Polignac number, because 666595 - 2⁷ = 666467 is a prime.

666595 is a lucky number.

It is a plaindrome in base 14.

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, 66655 + ... + 66664.

It is an arithmetic number, because the mean of its divisors is an integer number (199980).

2⁶⁶⁶⁵⁹⁵ is an apocalyptic number.

666595 is a deficient number, since it is larger than the sum of its proper divisors (133325).

666595 is a wasteful number, since it uses less digits than its factorization.

666595 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133324.

The product of its digits is 48600, while the sum is 37.

The square root of 666595 is about 816.4526930570. The cubic root of 666595 is about 87.3549160315.

The spelling of 666595 in words is "six hundred sixty-six thousand, five hundred ninety-five".