406666 has 8 divisors (see below), whose sum is σ = 656964. Its totient is φ = 187680.

The previous prime is 406661. The next prime is 406673. The reversal of 406666 is 666604.

It can be written as a sum of positive squares in 2 ways, for example, as 395641 + 11025 = 629^2 + 105^2 .

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

406666 is a modest number, since divided by 666 gives 406 as remainder.

It is not an unprimeable number, because it can be changed into a prime (406661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7795 + ... + 7846.

2⁴⁰⁶⁶⁶⁶ is an apocalyptic number.

406666 is a deficient number, since it is larger than the sum of its proper divisors (250298).

406666 is a wasteful number, since it uses less digits than its factorization.

406666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15656.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 406666 is about 637.7036929484. The cubic root of 406666 is about 74.0876730526.

The spelling of 406666 in words is "four hundred six thousand, six hundred sixty-six".