21231224444400 has 240 divisors, whose sum is σ = 68525048901888. Its totient is φ = 5618862848000.

The previous prime is 21231224444317. The next prime is 21231224444453. The reversal of 21231224444400 is 444442213212.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 721865695 + ... + 721895105.

Almost surely, 2^{21231224444400} is an apocalyptic number.

21231224444400 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 21231224444400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34262524450944).

21231224444400 is an abundant number, since it is smaller than the sum of its proper divisors (47293824457488).

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

21231224444400 is a wasteful number, since it uses less digits than its factorization.

21231224444400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33960 (or 33949 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 33.

Adding to 21231224444400 its reverse (444442213212), we get a palindrome (21675666657612).

The spelling of 21231224444400 in words is "twenty-one trillion, two hundred thirty-one billion, two hundred twenty-four million, four hundred forty-four thousand, four hundred".