21575567760 has 120 divisors (see below), whose sum is σ = 68556653760. Its totient is φ = 5613050880.

The previous prime is 21575567723. The next prime is 21575567773. The reversal of 21575567760 is 6776557512.

It is a tau number, because it is divible by the number of its divisors (120).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 376701 + ... + 430179.

It is an arithmetic number, because the mean of its divisors is an integer number (571305448).

Almost surely, 2^21575567760 is an apocalyptic number.

21575567760 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 21575567760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34278326880).

21575567760 is an abundant number, since it is smaller than the sum of its proper divisors (46981086000).

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

21575567760 is a wasteful number, since it uses less digits than its factorization.

21575567760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53577 (or 53530 counting only the distinct ones).

The product of its (nonzero) digits is 3087000, while the sum is 51.

The spelling of 21575567760 in words is "twenty-one billion, five hundred seventy-five million, five hundred sixty-seven thousand, seven hundred sixty".