6666191 has 4 divisors (see below), whose sum is σ = 7618512. Its totient is φ = 5713872.

The previous prime is 6666173. The next prime is 6666203. The reversal of 6666191 is 1916666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1916666 = 2 ⋅958333.

It is a cyclic number.

It is not a de Polignac number, because 6666191 - 2¹⁰ = 6665167 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6666391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 476150 + ... + 476163.

It is an arithmetic number, because the mean of its divisors is an integer number (1904628).

Almost surely, 2^6666191 is an apocalyptic number.

6666191 is a deficient number, since it is larger than the sum of its proper divisors (952321).

6666191 is an equidigital number, since it uses as much as digits as its factorization.

6666191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 952320.

The product of its digits is 11664, while the sum is 35.

The square root of 6666191 is about 2581.8967833746. The cubic root of 6666191 is about 188.2027294750.

The spelling of 6666191 in words is "six million, six hundred sixty-six thousand, one hundred ninety-one".