989820 has 120 divisors (see below), whose sum is σ = 3415104. Its totient is φ = 238464.

The previous prime is 989803. The next prime is 989827. The reversal of 989820 is 28989.

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (989827) by changing a digit.

989820 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 21037 + ... + 21083.

2⁹⁸⁹⁸²⁰ is an apocalyptic number.

989820 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 989820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1707552).

989820 is an abundant number, since it is smaller than the sum of its proper divisors (2425284).

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

989820 is a wasteful number, since it uses less digits than its factorization.

989820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 70 counting only the distinct ones).

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

The square root of 989820 is about 994.8969795914. The cubic root of 989820 is about 99.6595086388.

989820 divided by its sum of digits (36) gives a triangular number (27495 = T₂₃₄).

The spelling of 989820 in words is "nine hundred eighty-nine thousand, eight hundred twenty".