21915343539648 has 252 divisors, whose sum is σ = 69172999875720. Its totient is φ = 6628889659392.

The previous prime is 21915343539629. The next prime is 21915343539737. The reversal of 21915343539648 is 84693534351912.

21915343539648 is a `hidden beast` number, since 2 + 1 + 9 + 1 + 5 + 34 + 3 + 539 + 64 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3835390 + ... + 7651202.

Almost surely, 2^{21915343539648} 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 21915343539648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34586499937860).

21915343539648 is an abundant number, since it is smaller than the sum of its proper divisors (47257656336072).

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

21915343539648 is a wasteful number, since it uses less digits than its factorization.

21915343539648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3815916 (or 3815890 counting only the distinct ones).

The product of its digits is 83980800, while the sum is 63.

The spelling of 21915343539648 in words is "twenty-one trillion, nine hundred fifteen billion, three hundred forty-three million, five hundred thirty-nine thousand, six hundred forty-eight".