409666 has 8 divisors (see below), whose sum is σ = 650700. Its totient is φ = 192768.

The previous prime is 409657. The next prime is 409691. The reversal of 409666 is 666904.

409666 = T₇₄ + T₇₅ + ... + T₁₄₁.

It can be written as a sum of positive squares in 2 ways, for example, as 385641 + 24025 = 621^2 + 155^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5991 + ... + 6058.

2⁴⁰⁹⁶⁶⁶ is an apocalyptic number.

409666 is a deficient number, since it is larger than the sum of its proper divisors (241034).

409666 is a wasteful number, since it uses less digits than its factorization.

409666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12068.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 409666 is about 640.0515604231. The cubic root of 409666 is about 74.2694099890.

The spelling of 409666 in words is "four hundred nine thousand, six hundred sixty-six".