998857 has 2 divisors, whose sum is σ = 998858. Its totient is φ = 998856.

The previous prime is 998843. The next prime is 998861. The reversal of 998857 is 758899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 978121 + 20736 = 989^2 + 144^2 .

It is an emirp because it is prime and its reverse (758899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998857 - 2¹⁹ = 474569 is a prime.

It is not a weakly prime, because it can be changed into another prime (998897) 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, 499428 + 499429.

It is an arithmetic number, because the mean of its divisors is an integer number (499429).

2⁹⁹⁸⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

998857 is a deficient number, since it is larger than the sum of its proper divisors (1).

998857 is an equidigital number, since it uses as much as digits as its factorization.

998857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 46.

The square root of 998857 is about 999.4283366005. The cubic root of 998857 is about 99.9618854747.

The spelling of 998857 in words is "nine hundred ninety-eight thousand, eight hundred fifty-seven".