21321313200 has 270 divisors, whose sum is σ = 81330479412. Its totient is φ = 5168697600.

The previous prime is 21321313193. The next prime is 21321313217. The reversal of 21321313200 is 231312312.

21321313200 is a `hidden beast` number, since 21 + 321 + 3 + 1 + 320 + 0 = 666.

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 53 ways as a sum of consecutive naturals, for example, 411127 + ... + 460073.

Almost surely, 2^21321313200 is an apocalyptic number.

21321313200 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 21321313200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40665239706).

21321313200 is an abundant number, since it is smaller than the sum of its proper divisors (60009166212).

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

21321313200 is a wasteful number, since it uses less digits than its factorization.

21321313200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48993 (or 48968 counting only the distinct ones).

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

Adding to 21321313200 its reverse (231312312), we get a palindrome (21552625512).

The spelling of 21321313200 in words is "twenty-one billion, three hundred twenty-one million, three hundred thirteen thousand, two hundred".