9919997 has 2 divisors, whose sum is σ = 9919998. Its totient is φ = 9919996.

The previous prime is 9919979. The next prime is 9920021. The reversal of 9919997 is 7999199.

Together with previous prime (9919979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6895876 + 3024121 = 2626^2 + 1739^2 .

It is a cyclic number.

It is not a de Polignac number, because 9919997 - 2⁶ = 9919933 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9919937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4959998 + 4959999.

It is an arithmetic number, because the mean of its divisors is an integer number (4959999).

Almost surely, 2^9919997 is an apocalyptic number.

It is an amenable number.

9919997 is a deficient number, since it is larger than the sum of its proper divisors (1).

9919997 is an equidigital number, since it uses as much as digits as its factorization.

9919997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 413343, while the sum is 53.

The square root of 9919997 is about 3149.6026733542. The cubic root of 9919997 is about 214.8673925378.

The spelling of 9919997 in words is "nine million, nine hundred nineteen thousand, nine hundred ninety-seven".