21534708512016 has 360 divisors, whose sum is σ = 71835201737208. Its totient is φ = 6001164288000.

The previous prime is 21534708512011. The next prime is 21534708512017. The reversal of 21534708512016 is 61021580743512.

21534708512016 is a `hidden beast` number, since 2 + 1 + 53 + 4 + 70 + 8 + 512 + 0 + 16 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4821361977600 + 16713346534416 = 2195760^2 + 4088196^2 .

It is not an unprimeable number, because it can be changed into a prime (21534708512011) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1574052696 + ... + 1574066376.

Almost surely, 2^{21534708512016} 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 21534708512016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35917600868604).

21534708512016 is an abundant number, since it is smaller than the sum of its proper divisors (50300493225192).

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

21534708512016 is a wasteful number, since it uses less digits than its factorization.

21534708512016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19191 (or 19175 counting only the distinct ones).

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

The spelling of 21534708512016 in words is "twenty-one trillion, five hundred thirty-four billion, seven hundred eight million, five hundred twelve thousand, sixteen".