242840 has 32 divisors (see below), whose sum is σ = 589680. Its totient is φ = 89472.

The previous prime is 242819. The next prime is 242863. The reversal of 242840 is 48242.

242840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

242840 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 7 ways as a sum of consecutive naturals, for example, 287 + ... + 753.

2²⁴²⁸⁴⁰ is an apocalyptic number.

242840 is a gapful number since it is divisible by the number (20) 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 242840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294840).

242840 is an abundant number, since it is smaller than the sum of its proper divisors (346840).

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

242840 is a wasteful number, since it uses less digits than its factorization.

242840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 487 counting only the distinct ones).

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

The square root of 242840 is about 492.7879868666. The cubic root of 242840 is about 62.3888156593.

The spelling of 242840 in words is "two hundred forty-two thousand, eight hundred forty".