21344424400 has 60 divisors (see below), whose sum is σ = 55224606892. Its totient is φ = 7881016320.

The previous prime is 21344424379. The next prime is 21344424401. The reversal of 21344424400 is 442444312.

It can be written as a sum of positive squares in 6 ways, for example, as 4065847696 + 17278576704 = 63764^2 + 131448^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344424401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2047149 + ... + 2057548.

Almost surely, 2^21344424400 is an apocalyptic number.

21344424400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21344424400 is an abundant number, since it is smaller than the sum of its proper divisors (33880182492).

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

21344424400 is a wasteful number, since it uses less digits than its factorization.

21344424400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4104728 (or 4104717 counting only the distinct ones).

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

Adding to 21344424400 its reverse (442444312), we get a palindrome (21786868712).

The spelling of 21344424400 in words is "twenty-one billion, three hundred forty-four million, four hundred twenty-four thousand, four hundred".