666705 has 24 divisors (see below), whose sum is σ = 1159488. Its totient is φ = 326976.

The previous prime is 666697. The next prime is 666707. The reversal of 666705 is 507666.

It is not a de Polignac number, because 666705 - 2³ = 666697 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (666707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2404 + ... + 2666.

It is an arithmetic number, because the mean of its divisors is an integer number (48312).

2⁶⁶⁶⁷⁰⁵ is an apocalyptic number.

666705 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

666705 is a deficient number, since it is larger than the sum of its proper divisors (492783).

666705 is a wasteful number, since it uses less digits than its factorization.

666705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 284 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 30.

The square root of 666705 is about 816.5200548670. The cubic root of 666705 is about 87.3597208041.

The spelling of 666705 in words is "six hundred sixty-six thousand, seven hundred five".