21788478061920 has 240 divisors, whose sum is σ = 76939265996208. Its totient is φ = 5806928931840.

The previous prime is 21788478061919. The next prime is 21788478061943. The reversal of 21788478061920 is 2916087488712.

21788478061920 is a `hidden beast` number, since 2 + 1 + 7 + 8 + 8 + 4 + 7 + 8 + 0 + 619 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 22159950 + ... + 23122290.

Almost surely, 2^{21788478061920} is an apocalyptic number.

21788478061920 is a gapful number since it is divisible by the number (20) 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 21788478061920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38469632998104).

21788478061920 is an abundant number, since it is smaller than the sum of its proper divisors (55150787934288).

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

21788478061920 is a wasteful number, since it uses less digits than its factorization.

21788478061920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 964115 (or 964098 counting only the distinct ones).

The product of its (nonzero) digits is 21676032, while the sum is 63.

The spelling of 21788478061920 in words is "twenty-one trillion, seven hundred eighty-eight billion, four hundred seventy-eight million, sixty-one thousand, nine hundred twenty".