21416057856 has 220 divisors, whose sum is σ = 66023446720. Its totient is φ = 6907576320.

The previous prime is 21416057833. The next prime is 21416057863. The reversal of 21416057856 is 65875061412.

21416057856 is a `hidden beast` number, since 2 + 14 + 1 + 60 + 578 + 5 + 6 = 666.

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 19 ways as a sum of consecutive naturals, for example, 2567100 + ... + 2575428.

It is an arithmetic number, because the mean of its divisors is an integer number (300106576).

Almost surely, 2^21416057856 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 21416057856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33011723360).

21416057856 is an abundant number, since it is smaller than the sum of its proper divisors (44607388864).

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

21416057856 is an equidigital number, since it uses as much as digits as its factorization.

21416057856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8392 (or 8365 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 21416057856 in words is "twenty-one billion, four hundred sixteen million, fifty-seven thousand, eight hundred fifty-six".