998865 has 48 divisors (see below), whose sum is σ = 2079360. Its totient is φ = 453600.

The previous prime is 998861. The next prime is 998897. The reversal of 998865 is 568899.

It is not a de Polignac number, because 998865 - 2² = 998861 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 998865.

It is not an unprimeable number, because it can be changed into a prime (998861) 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 47 ways as a sum of consecutive naturals, for example, 6540 + ... + 6690.

It is an arithmetic number, because the mean of its divisors is an integer number (43320).

2⁹⁹⁸⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

998865 is an abundant number, since it is smaller than the sum of its proper divisors (1080495).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

998865 is a wasteful number, since it uses less digits than its factorization.

998865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 166 counting only the distinct ones).

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

The square root of 998865 is about 999.4323388804. The cubic root of 998865 is about 99.9621523440.

The spelling of 998865 in words is "nine hundred ninety-eight thousand, eight hundred sixty-five".