998685 has 12 divisors (see below), whose sum is σ = 1731132. Its totient is φ = 532608.

The previous prime is 998681. The next prime is 998687. The reversal of 998685 is 586899.

It can be written as a sum of positive squares in 2 ways, for example, as 700569 + 298116 = 837^2 + 546^2 .

It is not a de Polignac number, because 998685 - 2² = 998681 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 22193 = 998685 / (9 + 9 + 8 + 6 + 8 + 5).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 998685.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998681) 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 in 11 ways as a sum of consecutive naturals, for example, 11052 + ... + 11141.

It is an arithmetic number, because the mean of its divisors is an integer number (144261).

2⁹⁹⁸⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

998685 is a deficient number, since it is larger than the sum of its proper divisors (732447).

998685 is a wasteful number, since it uses less digits than its factorization.

998685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22204 (or 22201 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 998685 is about 999.3422837046. The cubic root of 998685 is about 99.9561474390.

The spelling of 998685 in words is "nine hundred ninety-eight thousand, six hundred eighty-five".