9967891 has 2 divisors, whose sum is σ = 9967892. Its totient is φ = 9967890.

The previous prime is 9967883. The next prime is 9967987. The reversal of 9967891 is 1987699.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9967891 - 2³ = 9967883 is a prime.

It is not a weakly prime, because it can be changed into another prime (9967801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4983945 + 4983946.

It is an arithmetic number, because the mean of its divisors is an integer number (4983946).

Almost surely, 2^9967891 is an apocalyptic number.

9967891 is a deficient number, since it is larger than the sum of its proper divisors (1).

9967891 is an equidigital number, since it uses as much as digits as its factorization.

9967891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 49.

The square root of 9967891 is about 3157.1966996055. The cubic root of 9967891 is about 215.2126326176.

The spelling of 9967891 in words is "nine million, nine hundred sixty-seven thousand, eight hundred ninety-one".