1001666 has 8 divisors (see below), whose sum is σ = 1512000.
Its totient is φ = 497668.
The previous prime is 1001659. The next prime is 1001669. The reversal of 1001666 is 6661001.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not an unprimeable number, because it can be changed into a prime (1001669) 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, 1166 + ... + 1833.
It is an arithmetic number, because the mean of its divisors is an integer number (189000).
21001666 is an apocalyptic number.
1001666 is a deficient number, since it is larger than the sum of its proper divisors (510334).
1001666 is a wasteful number, since it uses less digits than its factorization.
1001666 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 3168.
The product of its (nonzero) digits is 216, while the sum is 20.
The square root of 1001666 is about 1000.8326533442.
The cubic root of 1001666 is about 100.0555025223.
Adding to 1001666 its reverse (6661001), we get a palindrome (7662667).
It can be divided in two parts, 1001 and 666, that multiplied together give a palindrome (666666).
The spelling of 1001666 in words is "one million, one thousand, six hundred sixty-six".