21886438391808 has 360 divisors, whose sum is σ = 59927403775680. Its totient is φ = 7102808064000.

The previous prime is 21886438391747. The next prime is 21886438391833. The reversal of 21886438391808 is 80819383468812.

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 23 ways as a sum of consecutive naturals, for example, 66122170203 + ... + 66122170533.

It is an arithmetic number, because the mean of its divisors is an integer number (166465010488).

Almost surely, 2^{21886438391808} 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 21886438391808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29963701887840).

21886438391808 is an abundant number, since it is smaller than the sum of its proper divisors (38040965383872).

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

21886438391808 is an frugal number, since it uses more digits than its factorization.

21886438391808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723 (or 546 counting only the distinct ones).

The product of its (nonzero) digits is 127401984, while the sum is 69.

The spelling of 21886438391808 in words is "twenty-one trillion, eight hundred eighty-six billion, four hundred thirty-eight million, three hundred ninety-one thousand, eight hundred eight".