21570784560 has 480 divisors, whose sum is σ = 85287541248. Its totient is φ = 4835082240.

The previous prime is 21570784523. The next prime is 21570784567. The reversal of 21570784560 is 6548707512.

21570784560 is a `hidden beast` number, since 2 + 1 + 5 + 7 + 0 + 7 + 84 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (21570784567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4930534 + ... + 4934906.

Almost surely, 2^21570784560 is an apocalyptic number.

21570784560 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 21570784560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42643770624).

21570784560 is an abundant number, since it is smaller than the sum of its proper divisors (63716756688).

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

21570784560 is a wasteful number, since it uses less digits than its factorization.

21570784560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4453 (or 4444 counting only the distinct ones).

The product of its (nonzero) digits is 470400, while the sum is 45.

The spelling of 21570784560 in words is "twenty-one billion, five hundred seventy million, seven hundred eighty-four thousand, five hundred sixty".