666995 has 32 divisors (see below), whose sum is σ = 1036800. Its totient is φ = 400896.

The previous prime is 666989. The next prime is 667013. The reversal of 666995 is 599666.

666995 = T₂₆ + T₂₇ + ... + T₁₅₈.

666995 = 61² + 62² + ... + 130².

It is a cyclic number.

It is not a de Polignac number, because 666995 - 2⁴ = 666979 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 11276 + ... + 11334.

It is an arithmetic number, because the mean of its divisors is an integer number (32400).

2⁶⁶⁶⁹⁹⁵ is an apocalyptic number.

666995 is a deficient number, since it is larger than the sum of its proper divisors (369805).

666995 is a wasteful number, since it uses less digits than its factorization.

666995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107.

The product of its digits is 87480, while the sum is 41.

The square root of 666995 is about 816.6976184611. The cubic root of 666995 is about 87.3723853992.

It can be divided in two parts, 666 and 995, that added together give a palindrome (1661).

The spelling of 666995 in words is "six hundred sixty-six thousand, nine hundred ninety-five".