8391971 has 4 divisors (see below), whose sum is σ = 9590832. Its totient is φ = 7193112.

The previous prime is 8391959. The next prime is 8391997. The reversal of 8391971 is 1791938.

8391971 is digitally balanced in base 3, 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 8391971 - 2²² = 4197667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8397971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 599420 + ... + 599433.

It is an arithmetic number, because the mean of its divisors is an integer number (2397708).

Almost surely, 2^8391971 is an apocalyptic number.

8391971 is a deficient number, since it is larger than the sum of its proper divisors (1198861).

8391971 is a wasteful number, since it uses less digits than its factorization.

8391971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1198860.

The product of its digits is 13608, while the sum is 38.

The square root of 8391971 is about 2896.8898839963. The cubic root of 8391971 is about 203.2144836820.

The spelling of 8391971 in words is "eight million, three hundred ninety-one thousand, nine hundred seventy-one".