21663221160565 has 8 divisors (see below), whose sum is σ = 25996080489120. Its totient is φ = 17330433530832.

The previous prime is 21663221160521. The next prime is 21663221160587. The reversal of 21663221160565 is 56506112236612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21663221160565 - 2¹³ = 21663221152373 is a prime.

It is a super-3 number, since 3×21663221160565³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17257735 + ... + 18470404.

It is an arithmetic number, because the mean of its divisors is an integer number (3249510061140).

Almost surely, 2^{21663221160565} is an apocalyptic number.

It is an amenable number.

21663221160565 is a deficient number, since it is larger than the sum of its proper divisors (4332859328555).

21663221160565 is a wasteful number, since it uses less digits than its factorization.

21663221160565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35849411.

The product of its (nonzero) digits is 777600, while the sum is 46.

The spelling of 21663221160565 in words is "twenty-one trillion, six hundred sixty-three billion, two hundred twenty-one million, one hundred sixty thousand, five hundred sixty-five".