665705 has 8 divisors (see below), whose sum is σ = 803904. Its totient is φ = 529200.

The previous prime is 665677. The next prime is 665713. The reversal of 665705 is 507566.

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

It is not a de Polignac number, because 665705 - 2¹⁴ = 649321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 740 + ... + 1370.

It is an arithmetic number, because the mean of its divisors is an integer number (100488).

2⁶⁶⁵⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

665705 is a deficient number, since it is larger than the sum of its proper divisors (138199).

665705 is a wasteful number, since it uses less digits than its factorization.

665705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847.

The product of its (nonzero) digits is 6300, while the sum is 29.

The square root of 665705 is about 815.9074702440. The cubic root of 665705 is about 87.3160215995.

The spelling of 665705 in words is "six hundred sixty-five thousand, seven hundred five".