409599666 has 80 divisors (see below), whose sum is σ = 1110675456. Its totient is φ = 110139264.

The previous prime is 409599647. The next prime is 409599703. The reversal of 409599666 is 666995904.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8655 + ... + 29901.

Almost surely, 2^409599666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 409599666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (555337728).

409599666 is an abundant number, since it is smaller than the sum of its proper divisors (701075790).

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

409599666 is a wasteful number, since it uses less digits than its factorization.

409599666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21285 (or 21276 counting only the distinct ones).

The product of its (nonzero) digits is 3149280, while the sum is 54.

The square root of 409599666 is about 20238.5687735077. The cubic root of 409599666 is about 742.6540115172.

It can be divided in two parts, 40959 and 9666, that added together give a 4-th power (50625 = 15⁴).

The spelling of 409599666 in words is "four hundred nine million, five hundred ninety-nine thousand, six hundred sixty-six".