243120639780 has 84 divisors (see below), whose sum is σ = 765479887452. Its totient is φ = 64832166720.

The previous prime is 243120639761. The next prime is 243120639791. The reversal of 243120639780 is 87936021342.

243120639780 is a `hidden beast` number, since 2 + 4 + 3 + 1 + 2 + 0 + 639 + 7 + 8 + 0 = 666.

243120639780 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 45083179584 + 198037460196 = 212328^2 + 445014^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 8322891 + ... + 8352050.

It is an arithmetic number, because the mean of its divisors is an integer number (9112855803).

Almost surely, 2^243120639780 is an apocalyptic number.

243120639780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

243120639780 is an abundant number, since it is smaller than the sum of its proper divisors (522359247672).

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

243120639780 is a wasteful number, since it uses less digits than its factorization.

243120639780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16674968 (or 16674951 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 243120639780 in words is "two hundred forty-three billion, one hundred twenty million, six hundred thirty-nine thousand, seven hundred eighty".