21570559671 has 16 divisors (see below), whose sum is σ = 29103187680. Its totient is φ = 14209367040.

The previous prime is 21570559669. The next prime is 21570559679. The reversal of 21570559671 is 17695507512.

It is not a de Polignac number, because 21570559671 - 2¹ = 21570559669 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21570559671.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21570559679) 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 15 ways as a sum of consecutive naturals, for example, 388641 + ... + 440661.

It is an arithmetic number, because the mean of its divisors is an integer number (1818949230).

Almost surely, 2^21570559671 is an apocalyptic number.

21570559671 is a deficient number, since it is larger than the sum of its proper divisors (7532628009).

21570559671 is a wasteful number, since it uses less digits than its factorization.

21570559671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53666.

The product of its (nonzero) digits is 661500, while the sum is 48.

The spelling of 21570559671 in words is "twenty-one billion, five hundred seventy million, five hundred fifty-nine thousand, six hundred seventy-one".