999817813 has 2 divisors, whose sum is σ = 999817814.
Its totient is φ = 999817812.
The previous prime is 999817789. The next prime is 999817817. The reversal of 999817813 is 318718999.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 993951729 + 5866084 = 31527^2 + 2422^2
It is a cyclic number.
It is not a de Polignac number, because 999817813 - 217 = 999686741 is a prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (999817817) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499908906 + 499908907.
It is an arithmetic number, because the mean of its divisors is an integer number (499908907).
Almost surely, 2999817813 is an apocalyptic number.
It is an amenable number.
999817813 is a deficient number, since it is larger than the sum of its proper divisors (1).
999817813 is an equidigital number, since it uses as much as digits as its factorization.
999817813 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 979776, while the sum is 55.
The square root of 999817813 is about 31619.8958410682.
The cubic root of 999817813 is about 999.9392673116.
The spelling of 999817813 in words is "nine hundred ninety-nine million, eight hundred seventeen thousand, eight hundred thirteen".