243520 has 28 divisors (see below), whose sum is σ = 580644. Its totient is φ = 97280.

The previous prime is 243517. The next prime is 243521. The reversal of 243520 is 25342.

243520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 28224 + 215296 = 168^2 + 464^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 243494 and 243503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61 + ... + 700.

2²⁴³⁵²⁰ is an apocalyptic number.

243520 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 243520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (290322).

243520 is an abundant number, since it is smaller than the sum of its proper divisors (337124).

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

243520 is an equidigital number, since it uses as much as digits as its factorization.

243520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778 (or 768 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 16.

The square root of 243520 is about 493.4774564253. The cubic root of 243520 is about 62.4469950603.

Adding to 243520 its reverse (25342), we get a palindrome (268862).

The spelling of 243520 in words is "two hundred forty-three thousand, five hundred twenty".