9916891 has 2 divisors, whose sum is σ = 9916892.
Its totient is φ = 9916890.
The previous prime is 9916889. The next prime is 9916903. The reversal of 9916891 is 1986199.
It is a weak prime.
It is an emirp because it is prime and its reverse (1986199) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 9916891 - 21 = 9916889 is a prime.
Together with 9916889, it forms a pair of twin primes.
It is not a weakly prime, because it can be changed into another prime (9916091) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4958445 + 4958446.
It is an arithmetic number, because the mean of its divisors is an integer number (4958446).
Almost surely, 29916891 is an apocalyptic number.
9916891 is a deficient number, since it is larger than the sum of its proper divisors (1).
9916891 is an equidigital number, since it uses as much as digits as its factorization.
9916891 is an evil number, because the sum of its binary digits is even.
The product of its digits is 34992, while the sum is 43.
The square root of 9916891 is about 3149.1095566842.
The cubic root of 9916891 is about 214.8449648500.
The spelling of 9916891 in words is "nine million, nine hundred sixteen thousand, eight hundred ninety-one".