21563382852 has 144 divisors (see below), whose sum is σ = 60364729152. Its totient is φ = 6435901440.

The previous prime is 21563382833. The next prime is 21563382857. The reversal of 21563382852 is 25828336512.

21563382852 is a `hidden beast` number, since 2 + 1 + 5 + 633 + 8 + 2 + 8 + 5 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21563382798 and 21563382807.

It is not an unprimeable number, because it can be changed into a prime (21563382857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8718288 + ... + 8720760.

It is an arithmetic number, because the mean of its divisors is an integer number (419199508).

Almost surely, 2^21563382852 is an apocalyptic number.

21563382852 is a gapful number since it is divisible by the number (22) 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 21563382852, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30182364576).

21563382852 is an abundant number, since it is smaller than the sum of its proper divisors (38801346300).

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

21563382852 is a wasteful number, since it uses less digits than its factorization.

21563382852 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2818 (or 2813 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The spelling of 21563382852 in words is "twenty-one billion, five hundred sixty-three million, three hundred eighty-two thousand, eight hundred fifty-two".