21688765863 has 8 divisors (see below), whose sum is σ = 29112438000. Its totient is φ = 14362135488.

The previous prime is 21688765831. The next prime is 21688765871. The reversal of 21688765863 is 36856788612.

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

It is not a de Polignac number, because 21688765863 - 2⁵ = 21688765831 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21688765797 and 21688765806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21688765363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24259918 + ... + 24260811.

It is an arithmetic number, because the mean of its divisors is an integer number (3639054750).

Almost surely, 2^21688765863 is an apocalyptic number.

21688765863 is a deficient number, since it is larger than the sum of its proper divisors (7423672137).

21688765863 is a wasteful number, since it uses less digits than its factorization.

21688765863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48520881.

The product of its digits is 23224320, while the sum is 60.

The spelling of 21688765863 in words is "twenty-one billion, six hundred eighty-eight million, seven hundred sixty-five thousand, eight hundred sixty-three".