21331609200 has 720 divisors, whose sum is σ = 85229044992. Its totient is φ = 5080320000.

The previous prime is 21331609193. The next prime is 21331609217. The reversal of 21331609200 is 290613312.

21331609200 is a `hidden beast` number, since 2 + 1 + 3 + 31 + 609 + 20 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (27).

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 143 ways as a sum of consecutive naturals, for example, 75913060 + ... + 75913340.

Almost surely, 2^21331609200 is an apocalyptic number.

21331609200 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 21331609200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42614522496).

21331609200 is an abundant number, since it is smaller than the sum of its proper divisors (63897435792).

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

21331609200 is a wasteful number, since it uses less digits than its factorization.

21331609200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 373 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The spelling of 21331609200 in words is "twenty-one billion, three hundred thirty-one million, six hundred nine thousand, two hundred".