21808539882 has 24 divisors (see below), whose sum is σ = 47306623104. Its totient is φ = 7261084584.

The previous prime is 21808539869. The next prime is 21808539911. The reversal of 21808539882 is 28893580812.

21808539882 is a `hidden beast` number, since 21 + 8 + 0 + 8 + 539 + 8 + 82 = 666.

It is a super-2 number, since 2×21808539882² (a number of 21 digits) contains 22 as substring.

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 11 ways as a sum of consecutive naturals, for example, 686428 + ... + 717495.

It is an arithmetic number, because the mean of its divisors is an integer number (1971109296).

Almost surely, 2^21808539882 is an apocalyptic number.

21808539882 is an abundant number, since it is smaller than the sum of its proper divisors (25498083222).

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

21808539882 is a wasteful number, since it uses less digits than its factorization.

21808539882 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404794 (or 1404791 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 54.

The spelling of 21808539882 in words is "twenty-one billion, eight hundred eight million, five hundred thirty-nine thousand, eight hundred eighty-two".