21572607573 has 18 divisors (see below), whose sum is σ = 34250725782. Its totient is φ = 13074306960.

The previous prime is 21572607547. The next prime is 21572607583. The reversal of 21572607573 is 37570627512.

21572607573 is a `hidden beast` number, since 2 + 1 + 5 + 72 + 6 + 0 + 7 + 573 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16682822244 + 4889785329 = 129162^2 + 69927^2 .

It is not a de Polignac number, because 21572607573 - 2¹⁴ = 21572591189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21572607583) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 9903690 + ... + 9905867.

It is an arithmetic number, because the mean of its divisors is an integer number (1902818099).

Almost surely, 2^21572607573 is an apocalyptic number.

It is an amenable number.

21572607573 is a deficient number, since it is larger than the sum of its proper divisors (12678118209).

21572607573 is a wasteful number, since it uses less digits than its factorization.

21572607573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19809585 (or 19809571 counting only the distinct ones).

The product of its (nonzero) digits is 617400, while the sum is 45.

The spelling of 21572607573 in words is "twenty-one billion, five hundred seventy-two million, six hundred seven thousand, five hundred seventy-three".