21530199168 has 640 divisors, whose sum is σ = 72938257920. Its totient is φ = 6267469824.

The previous prime is 21530199149. The next prime is 21530199179. The reversal of 21530199168 is 86199103512.

21530199168 is a `hidden beast` number, since 21 + 530 + 1 + 9 + 91 + 6 + 8 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 190532680 + ... + 190532792.

It is an arithmetic number, because the mean of its divisors is an integer number (113966028).

Almost surely, 2^21530199168 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21530199168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36469128960).

21530199168 is an abundant number, since it is smaller than the sum of its proper divisors (51408058752).

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

21530199168 is a wasteful number, since it uses less digits than its factorization.

21530199168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The spelling of 21530199168 in words is "twenty-one billion, five hundred thirty million, one hundred ninety-nine thousand, one hundred sixty-eight".