243723661640 has 32 divisors (see below), whose sum is σ = 548478061560. Its totient is φ = 97471718400.

The previous prime is 243723661567. The next prime is 243723661663. The reversal of 243723661640 is 46166327342.

It can be written as a sum of positive squares in 4 ways, for example, as 195157198756 + 48566462884 = 441766^2 + 220378^2 .

It is a junction number, because it is equal to n+sod(n) for n = 243723661591 and 243723661600.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 330971 + ... + 772650.

Almost surely, 2^243723661640 is an apocalyptic number.

243723661640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

243723661640 is an abundant number, since it is smaller than the sum of its proper divisors (304754399920).

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

243723661640 is a wasteful number, since it uses less digits than its factorization.

243723661640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1109153 (or 1109149 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 44.

Adding to 243723661640 its reverse (46166327342), we get a palindrome (289889988982).

The spelling of 243723661640 in words is "two hundred forty-three billion, seven hundred twenty-three million, six hundred sixty-one thousand, six hundred forty".