999999898667857 has 2 divisors, whose sum is σ = 999999898667858. Its totient is φ = 999999898667856.

The previous prime is 999999898667849. The next prime is 999999898667873. The reversal of 999999898667857 is 758766898999999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 961001922000961 + 38997976666896 = 31000031^2 + 6244836^2 .

It is a cyclic number.

It is not a de Polignac number, because 999999898667857 - 2³ = 999999898667849 is a prime.

It is not a weakly prime, because it can be changed into another prime (999999898667657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999949333928 + 499999949333929.

It is an arithmetic number, because the mean of its divisors is an integer number (499999949333929).

Almost surely, 2^{999999898667857} is an apocalyptic number.

It is an amenable number.

999999898667857 is a deficient number, since it is larger than the sum of its proper divisors (1).

999999898667857 is an equidigital number, since it uses as much as digits as its factorization.

999999898667857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21599122728960, while the sum is 118.

The spelling of 999999898667857 in words is "nine hundred ninety-nine trillion, nine hundred ninety-nine billion, eight hundred ninety-eight million, six hundred sixty-seven thousand, eight hundred fifty-seven".