21987632528640 has 432 divisors, whose sum is σ = 78911592859008. Its totient is φ = 5861950414848.

The previous prime is 21987632528629. The next prime is 21987632528663. The reversal of 21987632528640 is 4682523678912.

21987632528640 is a `hidden beast` number, since 2 + 1 + 9 + 8 + 7 + 63 + 2 + 528 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

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 47 ways as a sum of consecutive naturals, for example, 2176341829 + ... + 2176351931.

It is a 1-persistent number, because it is pandigital, but 2⋅21987632528640 = 43975265057280 is not.

Almost surely, 2^{21987632528640} is an apocalyptic number.

21987632528640 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 21987632528640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39455796429504).

21987632528640 is an abundant number, since it is smaller than the sum of its proper divisors (56923960330368).

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

21987632528640 is an equidigital number, since it uses as much as digits as its factorization.

21987632528640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17136 (or 17110 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 63.

The spelling of 21987632528640 in words is "twenty-one trillion, nine hundred eighty-seven billion, six hundred thirty-two million, five hundred twenty-eight thousand, six hundred forty".