393666 has 48 divisors (see below), whose sum is σ = 995904. Its totient is φ = 102816.

The previous prime is 393649. The next prime is 393667. The reversal of 393666 is 666393.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (393667) 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, 3771 + ... + 3873.

It is an arithmetic number, because the mean of its divisors is an integer number (20748).

2³⁹³⁶⁶⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 393666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (497952).

393666 is an abundant number, since it is smaller than the sum of its proper divisors (602238).

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

393666 is a wasteful number, since it uses less digits than its factorization.

393666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 128 counting only the distinct ones).

The product of its digits is 17496, while the sum is 33.

The square root of 393666 is about 627.4280835283. The cubic root of 393666 is about 73.2896479943.

It can be divided in two parts, 39366 and 6, that multiplied together give a square (236196 = 486²).

The spelling of 393666 in words is "three hundred ninety-three thousand, six hundred sixty-six".