21615005760 has 56 divisors (see below), whose sum is σ = 68627646336. Its totient is φ = 5764001280.

The previous prime is 21615005747. The next prime is 21615005761. The reversal of 21615005760 is 6750051612.

It is not an unprimeable number, because it can be changed into a prime (21615005761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11256856 + ... + 11258775.

Almost surely, 2^21615005760 is an apocalyptic number.

21615005760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21615005760 is an abundant number, since it is smaller than the sum of its proper divisors (47012640576).

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

21615005760 is a wasteful number, since it uses less digits than its factorization.

21615005760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22515651 (or 22515641 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 33.

The spelling of 21615005760 in words is "twenty-one billion, six hundred fifteen million, five thousand, seven hundred sixty".