9881991839 has 2 divisors, whose sum is σ = 9881991840. Its totient is φ = 9881991838.

The previous prime is 9881991797. The next prime is 9881991841. The reversal of 9881991839 is 9381991889.

9881991839 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9881991839 - 2⁸ = 9881991583 is a prime.

Together with 9881991841, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9881991859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4940995919 + 4940995920.

It is an arithmetic number, because the mean of its divisors is an integer number (4940995920).

Almost surely, 2^9881991839 is an apocalyptic number.

9881991839 is a deficient number, since it is larger than the sum of its proper divisors (1).

9881991839 is an equidigital number, since it uses as much as digits as its factorization.

9881991839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10077696, while the sum is 65.

The square root of 9881991839 is about 99408.2081067756. The cubic root of 9881991839 is about 2145.9264377777.

The spelling of 9881991839 in words is "nine billion, eight hundred eighty-one million, nine hundred ninety-one thousand, eight hundred thirty-nine".