9931318381 has 2 divisors, whose sum is σ = 9931318382. Its totient is φ = 9931318380.

The previous prime is 9931318351. The next prime is 9931318391. The reversal of 9931318381 is 1838131399.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9126745156 + 804573225 = 95534^2 + 28365^2 .

It is a cyclic number.

It is not a de Polignac number, because 9931318381 - 2⁷ = 9931318253 is a prime.

It is a super-2 number, since 2×9931318381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9931318351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4965659190 + 4965659191.

It is an arithmetic number, because the mean of its divisors is an integer number (4965659191).

Almost surely, 2^9931318381 is an apocalyptic number.

It is an amenable number.

9931318381 is a deficient number, since it is larger than the sum of its proper divisors (1).

9931318381 is an equidigital number, since it uses as much as digits as its factorization.

9931318381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 46.

The square root of 9931318381 is about 99656.0002257767. Note that the first 3 decimals coincide. The cubic root of 9931318381 is about 2149.4910193031.

The spelling of 9931318381 in words is "nine billion, nine hundred thirty-one million, three hundred eighteen thousand, three hundred eighty-one".