9991673 has 2 divisors, whose sum is σ = 9991674. Its totient is φ = 9991672.

The previous prime is 9991669. The next prime is 9991691. The reversal of 9991673 is 3761999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8133904 + 1857769 = 2852^2 + 1363^2 .

It is an emirp because it is prime and its reverse (3761999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9991673 - 2² = 9991669 is a prime.

It is not a weakly prime, because it can be changed into another prime (9991603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995836 + 4995837.

It is an arithmetic number, because the mean of its divisors is an integer number (4995837).

Almost surely, 2^9991673 is an apocalyptic number.

It is an amenable number.

9991673 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991673 is an equidigital number, since it uses as much as digits as its factorization.

9991673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91854, while the sum is 44.

The square root of 9991673 is about 3160.9607716642. The cubic root of 9991673 is about 215.3836524715.

The spelling of 9991673 in words is "nine million, nine hundred ninety-one thousand, six hundred seventy-three".