99971797 has 2 divisors, whose sum is σ = 99971798. Its totient is φ = 99971796.

The previous prime is 99971779. The next prime is 99971801. The reversal of 99971797 is 79717999.

Together with previous prime (99971779) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60357361 + 39614436 = 7769^2 + 6294^2 .

It is an emirp because it is prime and its reverse (79717999) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99971797 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 (99971717) 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, 49985898 + 49985899.

It is an arithmetic number, because the mean of its divisors is an integer number (49985899).

Almost surely, 2^99971797 is an apocalyptic number.

It is an amenable number.

99971797 is a deficient number, since it is larger than the sum of its proper divisors (1).

99971797 is an equidigital number, since it uses as much as digits as its factorization.

99971797 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2250423, while the sum is 58.

The square root of 99971797 is about 9998.5897505598. The cubic root of 99971797 is about 464.1152436818.

The spelling of 99971797 in words is "ninety-nine million, nine hundred seventy-one thousand, seven hundred ninety-seven".