842240 has 80 divisors (see below), whose sum is σ = 2356992. Its totient is φ = 282624.

The previous prime is 842209. The next prime is 842249. The reversal of 842240 is 42248.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (842249) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 17897 + ... + 17943.

2⁸⁴²²⁴⁰ is an apocalyptic number.

842240 is a gapful number since it is divisible by the number (80) 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 842240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1178496).

842240 is an abundant number, since it is smaller than the sum of its proper divisors (1514752).

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

842240 is an equidigital number, since it uses as much as digits as its factorization.

842240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 842240 is about 917.7363455808. The cubic root of 842240 is about 94.4376752806.

Adding to 842240 its reverse (42248), we get a palindrome (884488).

The spelling of 842240 in words is "eight hundred forty-two thousand, two hundred forty".