998820 has 72 divisors (see below), whose sum is σ = 3144960. Its totient is φ = 256320.

The previous prime is 998819. The next prime is 998831. The reversal of 998820 is 28899.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5491 + ... + 5669.

It is an arithmetic number, because the mean of its divisors is an integer number (43680).

2⁹⁹⁸⁸²⁰ is an apocalyptic number.

998820 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 998820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1572480).

998820 is an abundant number, since it is smaller than the sum of its proper divisors (2146140).

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

998820 is a wasteful number, since it uses less digits than its factorization.

998820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 998820 is about 999.4098258472. The cubic root of 998820 is about 99.9606511854.

The spelling of 998820 in words is "nine hundred ninety-eight thousand, eight hundred twenty".