9931381 has 2 divisors, whose sum is σ = 9931382. Its totient is φ = 9931380.

The previous prime is 9931379. The next prime is 9931393. The reversal of 9931381 is 1831399.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8797156 + 1134225 = 2966^2 + 1065^2 .

It is an emirp because it is prime and its reverse (1831399) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9931381 - 2¹ = 9931379 is a prime.

It is a super-2 number, since 2×9931381² = 197264657134322, which contains 22 as substring.

Together with 9931379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9931301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4965690 + 4965691.

It is an arithmetic number, because the mean of its divisors is an integer number (4965691).

Almost surely, 2^9931381 is an apocalyptic number.

It is an amenable number.

9931381 is a deficient number, since it is larger than the sum of its proper divisors (1).

9931381 is an equidigital number, since it uses as much as digits as its factorization.

9931381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 34.

The square root of 9931381 is about 3151.4093672514. The cubic root of 9931381 is about 214.9495536954.

The spelling of 9931381 in words is "nine million, nine hundred thirty-one thousand, three hundred eighty-one".