21573242880 has 416 divisors, whose sum is σ = 79816249344. Its totient is φ = 4873125888.

The previous prime is 21573242869. The next prime is 21573242923. The reversal of 21573242880 is 8824237512.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44297997 + ... + 44298483.

It is an arithmetic number, because the mean of its divisors is an integer number (191865984).

Almost surely, 2^21573242880 is an apocalyptic number.

21573242880 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 21573242880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39908124672).

21573242880 is an abundant number, since it is smaller than the sum of its proper divisors (58243006464).

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

21573242880 is a wasteful number, since it uses less digits than its factorization.

21573242880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629 (or 607 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 42.

The spelling of 21573242880 in words is "twenty-one billion, five hundred seventy-three million, two hundred forty-two thousand, eight hundred eighty".