1311666 has 8 divisors (see below), whose sum is σ = 2623344. Its totient is φ = 437220.

The previous prime is 1311643. The next prime is 1311689. The reversal of 1311666 is 6661131.

It is an interprime number because it is at equal distance from previous prime (1311643) and next prime (1311689).

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

1311666 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a nude number because it is divisible by every one of its digits.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109300 + ... + 109311.

It is an arithmetic number, because the mean of its divisors is an integer number (327918).

2^1311666 is an apocalyptic number.

1311666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1311666 is a wasteful number, since it uses less digits than its factorization.

1311666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218616.

The product of its digits is 648, while the sum is 24.

The square root of 1311666 is about 1145.2798784577. The cubic root of 1311666 is about 109.4647829869.

Adding to 1311666 its reverse (6661131), we get a palindrome (7972797).

The spelling of 1311666 in words is "one million, three hundred eleven thousand, six hundred sixty-six".