99817813 has 2 divisors, whose sum is σ = 99817814. Its totient is φ = 99817812.

The previous prime is 99817771. The next prime is 99817831. The reversal of 99817813 is 31871899.

Together with next prime (99817831) 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., 94809169 + 5008644 = 9737^2 + 2238^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99817813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99817853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49908906 + 49908907.

It is an arithmetic number, because the mean of its divisors is an integer number (49908907).

Almost surely, 2^99817813 is an apocalyptic number.

It is an amenable number.

99817813 is a deficient number, since it is larger than the sum of its proper divisors (1).

99817813 is an equidigital number, since it uses as much as digits as its factorization.

99817813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 46.

The square root of 99817813 is about 9990.8864972033. The cubic root of 99817813 is about 463.8768329572.

The spelling of 99817813 in words is "ninety-nine million, eight hundred seventeen thousand, eight hundred thirteen".