21333121200 has 240 divisors, whose sum is σ = 78380697600. Its totient is φ = 5505235200.

The previous prime is 21333121193. The next prime is 21333121217. The reversal of 21333121200 is 212133312.

21333121200 is a `hidden beast` number, since 213 + 331 + 2 + 120 + 0 = 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 an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 302941 + ... + 366659.

It is an arithmetic number, because the mean of its divisors is an integer number (326586240).

Almost surely, 2^21333121200 is an apocalyptic number.

21333121200 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 21333121200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39190348800).

21333121200 is an abundant number, since it is smaller than the sum of its proper divisors (57047576400).

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

21333121200 is a wasteful number, since it uses less digits than its factorization.

21333121200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63777 (or 63760 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21333121200 its reverse (212133312), we get a palindrome (21545254512).

The spelling of 21333121200 in words is "twenty-one billion, three hundred thirty-three million, one hundred twenty-one thousand, two hundred".