9999931 has 2 divisors, whose sum is σ = 9999932.
Its totient is φ = 9999930.
The previous prime is 9999929. The next prime is 9999937. The reversal of 9999931 is 1399999.
9999931 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 weak prime.
It is an emirp because it is prime and its reverse (1399999) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 9999931 - 21 = 9999929 is a prime.
It is a super-2 number, since 2×99999312 = 199997240009522, which contains 22 as substring.
Together with 9999929, it forms a pair of twin primes.
It is a Chen prime.
It is a nialpdrome in base 10.
It is not a weakly prime, because it can be changed into another prime (9999937) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999965 + 4999966.
It is an arithmetic number, because the mean of its divisors is an integer number (4999966).
Almost surely, 29999931 is an apocalyptic number.
9999931 is a deficient number, since it is larger than the sum of its proper divisors (1).
9999931 is an equidigital number, since it uses as much as digits as its factorization.
9999931 is an evil number, because the sum of its binary digits is even.
The product of its digits is 177147, while the sum is 49.
The square root of 9999931 is about 3162.2667502916.
The cubic root of 9999931 is about 215.4429734821.
The spelling of 9999931 in words is "nine million, nine hundred ninety-nine thousand, nine hundred thirty-one".