4128191 has 4 divisors (see below), whose sum is σ = 4144512. Its totient is φ = 4111872.

The previous prime is 4128181. The next prime is 4128193. The reversal of 4128191 is 1918214.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4128191 is a prime.

It is an Ulam number.

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 4128191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4128193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7775 + ... + 8288.

It is an arithmetic number, because the mean of its divisors is an integer number (1036128).

Almost surely, 2^4128191 is an apocalyptic number.

4128191 is a deficient number, since it is larger than the sum of its proper divisors (16321).

4128191 is a wasteful number, since it uses less digits than its factorization.

4128191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16320.

The product of its digits is 576, while the sum is 26.

The square root of 4128191 is about 2031.7950191887. The cubic root of 4128191 is about 160.4180603541.

The spelling of 4128191 in words is "four million, one hundred twenty-eight thousand, one hundred ninety-one".