20721570571 has 16 divisors (see below), whose sum is σ = 22511913984. Its totient is φ = 18959560704.

The previous prime is 20721570559. The next prime is 20721570631. The reversal of 20721570571 is 17507512702.

It is a cyclic number.

It is not a de Polignac number, because 20721570571 - 2²⁷ = 20587352843 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20721570571.

It is not an unprimeable number, because it can be changed into a prime (20721570671) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2004111 + ... + 2014423.

It is an arithmetic number, because the mean of its divisors is an integer number (1406994624).

Almost surely, 2^20721570571 is an apocalyptic number.

20721570571 is a deficient number, since it is larger than the sum of its proper divisors (1790343413).

20721570571 is a wasteful number, since it uses less digits than its factorization.

20721570571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11670.

The product of its (nonzero) digits is 34300, while the sum is 37.

The spelling of 20721570571 in words is "twenty billion, seven hundred twenty-one million, five hundred seventy thousand, five hundred seventy-one".