1287166 has 4 divisors (see below), whose sum is σ = 1930752. Its totient is φ = 643582.

The previous prime is 1287163. The next prime is 1287173. The reversal of 1287166 is 6617821.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) 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 (1287163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321790 + ... + 321793.

It is an arithmetic number, because the mean of its divisors is an integer number (482688).

2^1287166 is an apocalyptic number.

1287166 is a deficient number, since it is larger than the sum of its proper divisors (643586).

1287166 is an equidigital number, since it uses as much as digits as its factorization.

1287166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643585.

The product of its digits is 4032, while the sum is 31.

The square root of 1287166 is about 1134.5333842598. The cubic root of 1287166 is about 108.7789476821.

It can be divided in two parts, 12 and 87166, that added together give a palindrome (87178).

The spelling of 1287166 in words is "one million, two hundred eighty-seven thousand, one hundred sixty-six".