6171991 has 6 divisors (see below), whose sum is σ = 7179720. Its totient is φ = 5290236.

The previous prime is 6171967. The next prime is 6172021. The reversal of 6171991 is 1991716.

It is not a de Polignac number, because 6171991 - 2²¹ = 4074839 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 (6171911) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62931 + ... + 63028.

It is an arithmetic number, because the mean of its divisors is an integer number (1196620).

Almost surely, 2^6171991 is an apocalyptic number.

6171991 is a deficient number, since it is larger than the sum of its proper divisors (1007729).

6171991 is a wasteful number, since it uses less digits than its factorization.

6171991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125973 (or 125966 counting only the distinct ones).

The product of its digits is 3402, while the sum is 34.

The square root of 6171991 is about 2484.3492105580. The cubic root of 6171991 is about 183.4319972143.

The spelling of 6171991 in words is "six million, one hundred seventy-one thousand, nine hundred ninety-one".