21557408040960 has 768 divisors, whose sum is σ = 77395226388480. Its totient is φ = 5077393735680.

The previous prime is 21557408040953. The next prime is 21557408040983. The reversal of 21557408040960 is 6904080475512.

21557408040960 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (768).

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 63 ways as a sum of consecutive naturals, for example, 2804394237 + ... + 2804401923.

It is an arithmetic number, because the mean of its divisors is an integer number (100775034360).

Almost surely, 2^{21557408040960} is an apocalyptic number.

21557408040960 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 21557408040960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38697613194240).

21557408040960 is an abundant number, since it is smaller than the sum of its proper divisors (55837818347520).

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

21557408040960 is a wasteful number, since it uses less digits than its factorization.

21557408040960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7964 (or 7944 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 51.

The spelling of 21557408040960 in words is "twenty-one trillion, five hundred fifty-seven billion, four hundred eight million, forty thousand, nine hundred sixty".