9871391 has 2 divisors, whose sum is σ = 9871392. Its totient is φ = 9871390.

The previous prime is 9871357. The next prime is 9871403. The reversal of 9871391 is 1931789.

It is a strong prime.

It is an emirp because it is prime and its reverse (1931789) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9871391 - 2⁶ = 9871327 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9871321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4935695 + 4935696.

It is an arithmetic number, because the mean of its divisors is an integer number (4935696).

Almost surely, 2^9871391 is an apocalyptic number.

9871391 is a deficient number, since it is larger than the sum of its proper divisors (1).

9871391 is an equidigital number, since it uses as much as digits as its factorization.

9871391 is an odious number, because the sum of its binary digits is odd.

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

The square root of 9871391 is about 3141.8769867708. The cubic root of 9871391 is about 214.5158820602.

The spelling of 9871391 in words is "nine million, eight hundred seventy-one thousand, three hundred ninety-one".