9998820 has 72 divisors (see below), whose sum is σ = 32670456. Its totient is φ = 2460672.

The previous prime is 9998809. The next prime is 9998851. The reversal of 9998820 is 288999.

It can be written as a sum of positive squares in 4 ways, for example, as 576 + 9998244 = 24^2 + 3162^2 .

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

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, 204 + ... + 4476.

Almost surely, 2^9998820 is an apocalyptic number.

9998820 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 9998820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16335228).

9998820 is an abundant number, since it is smaller than the sum of its proper divisors (22671636).

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

9998820 is a wasteful number, since it uses less digits than its factorization.

9998820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4301 (or 4296 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 9998820 is about 3162.0910802822. The cubic root of 9998820 is about 215.4349945601.

The spelling of 9998820 in words is "nine million, nine hundred ninety-eight thousand, eight hundred twenty".