1331666 has 16 divisors (see below), whose sum is σ = 2315904. Its totient is φ = 562464.

The previous prime is 1331663. The next prime is 1331683. The reversal of 1331666 is 6661331.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 371 + ... + 1673.

It is an arithmetic number, because the mean of its divisors is an integer number (144744).

2^1331666 is an apocalyptic number.

1331666 is a deficient number, since it is larger than the sum of its proper divisors (984238).

1331666 is a wasteful number, since it uses less digits than its factorization.

1331666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385.

The product of its digits is 1944, while the sum is 26.

The square root of 1331666 is about 1153.9783360185. The cubic root of 1331666 is about 110.0183440481.

Adding to 1331666 its reverse (6661331), we get a palindrome (7992997).

It can be divided in two parts, 1331 and 666, that multiplied together give a triangular number (886446 = T₁₃₃₁).

The spelling of 1331666 in words is "one million, three hundred thirty-one thousand, six hundred sixty-six".