705666 has 32 divisors (see below), whose sum is σ = 1552320. Its totient is φ = 212544.

The previous prime is 705643. The next prime is 705689. The reversal of 705666 is 666507.

It is an interprime number because it is at equal distance from previous prime (705643) and next prime (705689).

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

705666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6420 + ... + 6528.

It is an arithmetic number, because the mean of its divisors is an integer number (48510).

2⁷⁰⁵⁶⁶⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 705666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (776160).

705666 is an abundant number, since it is smaller than the sum of its proper divisors (846654).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

705666 is a wasteful number, since it uses less digits than its factorization.

705666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210.

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

The square root of 705666 is about 840.0392847957. The cubic root of 705666 is about 89.0293216521.

The spelling of 705666 in words is "seven hundred five thousand, six hundred sixty-six".