21568656953 has 8 divisors (see below), whose sum is σ = 21675653376. Its totient is φ = 21461706000.

The previous prime is 21568656947. The next prime is 21568656979. The reversal of 21568656953 is 35965686512.

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 21568656953 - 2¹⁰ = 21568655929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21568656913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1321400 + ... + 1337622.

It is an arithmetic number, because the mean of its divisors is an integer number (2709456672).

Almost surely, 2^21568656953 is an apocalyptic number.

It is an amenable number.

21568656953 is a deficient number, since it is larger than the sum of its proper divisors (106996423).

21568656953 is a wasteful number, since it uses less digits than its factorization.

21568656953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22735.

The product of its digits is 11664000, while the sum is 56.

The spelling of 21568656953 in words is "twenty-one billion, five hundred sixty-eight million, six hundred fifty-six thousand, nine hundred fifty-three".