21775777984128 has 512 divisors, whose sum is σ = 70656565248000. Its totient is φ = 5803583385600.

The previous prime is 21775777984063. The next prime is 21775777984141. The reversal of 21775777984128 is 82148977757712.

It is a super-3 number, since 3×21775777984128³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21775777984128.

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 63 ways as a sum of consecutive naturals, for example, 3114826713 + ... + 3114833703.

It is an arithmetic number, because the mean of its divisors is an integer number (138001104000).

Almost surely, 2^{21775777984128} is an apocalyptic number.

21775777984128 is a gapful number since it is divisible by the number (28) 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 21775777984128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35328282624000).

21775777984128 is an abundant number, since it is smaller than the sum of its proper divisors (48880787263872).

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

21775777984128 is a wasteful number, since it uses less digits than its factorization.

21775777984128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7964 (or 7952 counting only the distinct ones).

The product of its digits is 774466560, while the sum is 75.

The spelling of 21775777984128 in words is "twenty-one trillion, seven hundred seventy-five billion, seven hundred seventy-seven million, nine hundred eighty-four thousand, one hundred twenty-eight".