6391971 has 6 divisors (see below), whose sum is σ = 9232860. Its totient is φ = 4261308.

The previous prime is 6391963. The next prime is 6391991. The reversal of 6391971 is 1791936.

6391971 is a `hidden beast` number, since 639 + 19 + 7 + 1 = 666.

It is not a de Polignac number, because 6391971 - 2³ = 6391963 is a prime.

6391971 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6391901) 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, 355101 + ... + 355118.

It is an arithmetic number, because the mean of its divisors is an integer number (1538810).

Almost surely, 2^6391971 is an apocalyptic number.

6391971 is a deficient number, since it is larger than the sum of its proper divisors (2840889).

6391971 is a wasteful number, since it uses less digits than its factorization.

6391971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710225 (or 710222 counting only the distinct ones).

The product of its digits is 10206, while the sum is 36.

The square root of 6391971 is about 2528.2347596693. The cubic root of 6391971 is about 185.5858806113.

The spelling of 6391971 in words is "six million, three hundred ninety-one thousand, nine hundred seventy-one".