21324220400 has 120 divisors (see below), whose sum is σ = 58600918944. Its totient is φ = 7304832000.

The previous prime is 21324220321. The next prime is 21324220433. The reversal of 21324220400 is 402242312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 4177850 + ... + 4182950.

Almost surely, 2^21324220400 is an apocalyptic number.

21324220400 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 21324220400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29300459472).

21324220400 is an abundant number, since it is smaller than the sum of its proper divisors (37276698544).

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

21324220400 is a wasteful number, since it uses less digits than its factorization.

21324220400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6619 (or 6608 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21324220400 its reverse (402242312), we get a palindrome (21726462712).

The spelling of 21324220400 in words is "twenty-one billion, three hundred twenty-four million, two hundred twenty thousand, four hundred".