2166191 has 4 divisors (see below), whose sum is σ = 2293632. Its totient is φ = 2038752.

The previous prime is 2166179. The next prime is 2166221. The reversal of 2166191 is 1916612.

2166191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 2166191 - 2⁶ = 2166127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2166191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166121) 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 3 ways as a sum of consecutive naturals, for example, 63695 + ... + 63728.

It is an arithmetic number, because the mean of its divisors is an integer number (573408).

2^2166191 is an apocalyptic number.

2166191 is a deficient number, since it is larger than the sum of its proper divisors (127441).

2166191 is a wasteful number, since it uses less digits than its factorization.

2166191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127440.

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

The square root of 2166191 is about 1471.7985595862. The cubic root of 2166191 is about 129.3894645702.

The spelling of 2166191 in words is "two million, one hundred sixty-six thousand, one hundred ninety-one".