21324200400 has 240 divisors, whose sum is σ = 76080755520. Its totient is φ = 5672793600.

The previous prime is 21324200341. The next prime is 21324200431. The reversal of 21324200400 is 400242312.

21324200400 is a `hidden beast` number, since 21 + 3 + 242 + 0 + 0 + 400 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (18).

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, 4976659 + ... + 4980941.

It is an arithmetic number, because the mean of its divisors is an integer number (317003148).

Almost surely, 2^21324200400 is an apocalyptic number.

21324200400 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 21324200400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38040377760).

21324200400 is an abundant number, since it is smaller than the sum of its proper divisors (54756555120).

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

21324200400 is a wasteful number, since it uses less digits than its factorization.

21324200400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4771 (or 4754 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21324200400 its reverse (400242312), we get a palindrome (21724442712).

The spelling of 21324200400 in words is "twenty-one billion, three hundred twenty-four million, two hundred thousand, four hundred".