84420 has 72 divisors (see below), whose sum is σ = 297024. Its totient is φ = 19008.

The previous prime is 84407. The next prime is 84421. The reversal of 84420 is 2448.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 84393 and 84402.

It is not an unprimeable number, because it can be changed into a prime (84421) by changing a digit.

84420 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1227 + ... + 1293.

2⁸⁴⁴²⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 84420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148512).

84420 is an abundant number, since it is smaller than the sum of its proper divisors (212604).

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

84420 is a wasteful number, since it uses less digits than its factorization.

84420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 84420 is about 290.5512003073. The cubic root of 84420 is about 43.8680620680.

Adding to 84420 its reverse (2448), we get a palindrome (86868).

The spelling of 84420 in words is "eighty-four thousand, four hundred twenty".