21344242240 has 56 divisors (see below), whose sum is σ = 51522279480. Its totient is φ = 8420732928.

The previous prime is 21344242229. The next prime is 21344242253. The reversal of 21344242240 is 4224244312.

It can be written as a sum of positive squares in 4 ways, for example, as 7043909184 + 14300333056 = 83928^2 + 119584^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21344242199 and 21344242208.

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, 433495 + ... + 480214.

It is an arithmetic number, because the mean of its divisors is an integer number (920040705).

Almost surely, 2^21344242240 is an apocalyptic number.

21344242240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21344242240 is an abundant number, since it is smaller than the sum of its proper divisors (30178037240).

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

21344242240 is an equidigital number, since it uses as much as digits as its factorization.

21344242240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913799 (or 913789 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 28.

Adding to 21344242240 its reverse (4224244312), we get a palindrome (25568486552).

The spelling of 21344242240 in words is "twenty-one billion, three hundred forty-four million, two hundred forty-two thousand, two hundred forty".