1166391 has 18 divisors (see below), whose sum is σ = 1783080. Its totient is φ = 734616.

The previous prime is 1166383. The next prime is 1166393. The reversal of 1166391 is 1936611.

It is not a de Polignac number, because 1166391 - 2³ = 1166383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1166393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3070 + ... + 3428.

It is an arithmetic number, because the mean of its divisors is an integer number (99060).

2^1166391 is an apocalyptic number.

1166391 is a deficient number, since it is larger than the sum of its proper divisors (616689).

1166391 is a wasteful number, since it uses less digits than its factorization.

1166391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403 (or 381 counting only the distinct ones).

The product of its digits is 972, while the sum is 27.

The square root of 1166391 is about 1079.9958333253. The cubic root of 1166391 is about 105.2643678326.

The spelling of 1166391 in words is "one million, one hundred sixty-six thousand, three hundred ninety-one".