21063887544 has 96 divisors (see below), whose sum is σ = 61663420800. Its totient is φ = 5978347200.

The previous prime is 21063887503. The next prime is 21063887557. The reversal of 21063887544 is 44578836012.

It is a junction number, because it is equal to n+sod(n) for n = 21063887493 and 21063887502.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 118267 + ... + 236885.

It is an arithmetic number, because the mean of its divisors is an integer number (642327300).

Almost surely, 2^21063887544 is an apocalyptic number.

21063887544 is a gapful number since it is divisible by the number (24) 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 21063887544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30831710400).

21063887544 is an abundant number, since it is smaller than the sum of its proper divisors (40599533256).

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

21063887544 is a wasteful number, since it uses less digits than its factorization.

21063887544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118793 (or 118782 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 48.

The spelling of 21063887544 in words is "twenty-one billion, sixty-three million, eight hundred eighty-seven thousand, five hundred forty-four".