243720 has 48 divisors (see below), whose sum is σ = 793260. Its totient is φ = 64896.

The previous prime is 243709. The next prime is 243769. The reversal of 243720 is 27342.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 224676 + 19044 = 474^2 + 138^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 243693 and 243702.

It is an unprimeable number.

243720 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 11 ways as a sum of consecutive naturals, for example, 22 + ... + 698.

2²⁴³⁷²⁰ is an apocalyptic number.

243720 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 243720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (396630).

243720 is an abundant number, since it is smaller than the sum of its proper divisors (549540).

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

243720 is a wasteful number, since it uses less digits than its factorization.

243720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 18.

The square root of 243720 is about 493.6800583374. The cubic root of 243720 is about 62.4640860336.

The spelling of 243720 in words is "two hundred forty-three thousand, seven hundred twenty", and thus it is an iban number.