1291166 has 4 divisors (see below), whose sum is σ = 1936752. Its totient is φ = 645582.

The previous prime is 1291163. The next prime is 1291177. The reversal of 1291166 is 6611921.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322790 + ... + 322793.

It is an arithmetic number, because the mean of its divisors is an integer number (484188).

2^1291166 is an apocalyptic number.

1291166 is a deficient number, since it is larger than the sum of its proper divisors (645586).

1291166 is an equidigital number, since it uses as much as digits as its factorization.

1291166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645585.

The product of its digits is 648, while the sum is 26.

The square root of 1291166 is about 1136.2948561003. The cubic root of 1291166 is about 108.8915117297.

The spelling of 1291166 in words is "one million, two hundred ninety-one thousand, one hundred sixty-six".