243993780 has 72 divisors (see below), whose sum is σ = 747498024. Its totient is φ = 64416000.

The previous prime is 243993773. The next prime is 243993793. The reversal of 243993780 is 87399342.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 146458404 + 97535376 = 12102^2 + 9876^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11470 + ... + 24890.

It is an arithmetic number, because the mean of its divisors is an integer number (10381917).

Almost surely, 2^243993780 is an apocalyptic number.

243993780 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 243993780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373749012).

243993780 is an abundant number, since it is smaller than the sum of its proper divisors (503504244).

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

243993780 is a wasteful number, since it uses less digits than its factorization.

243993780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13537 (or 13532 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 243993780 is about 15620.3002531962. The cubic root of 243993780 is about 624.8746671350.

The spelling of 243993780 in words is "two hundred forty-three million, nine hundred ninety-three thousand, seven hundred eighty".