9981911 has 2 divisors, whose sum is σ = 9981912. Its totient is φ = 9981910.

The previous prime is 9981899. The next prime is 9981913. The reversal of 9981911 is 1191899.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (1191899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9981911 - 2⁶ = 9981847 is a prime.

Together with 9981913, 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 (9981913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4990955 + 4990956.

It is an arithmetic number, because the mean of its divisors is an integer number (4990956).

Almost surely, 2^9981911 is an apocalyptic number.

9981911 is a deficient number, since it is larger than the sum of its proper divisors (1).

9981911 is an equidigital number, since it uses as much as digits as its factorization.

9981911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 38.

The square root of 9981911 is about 3159.4162435488. The cubic root of 9981911 is about 215.3134853655.

The spelling of 9981911 in words is "nine million, nine hundred eighty-one thousand, nine hundred eleven".