21688932064 has 12 divisors (see below), whose sum is σ = 42700085064. Its totient is φ = 10844466016.

The previous prime is 21688932047. The next prime is 21688932071. The reversal of 21688932064 is 46023988612.

It is a junction number, because it is equal to n+sod(n) for n = 21688931999 and 21688932017.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 338889532 + ... + 338889595.

It is an arithmetic number, because the mean of its divisors is an integer number (3558340422).

Almost surely, 2^21688932064 is an apocalyptic number.

It is an amenable number.

21688932064 is a deficient number, since it is larger than the sum of its proper divisors (21011153000).

21688932064 is an equidigital number, since it uses as much as digits as its factorization.

21688932064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677779137 (or 677779129 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 49.

The spelling of 21688932064 in words is "twenty-one billion, six hundred eighty-eight million, nine hundred thirty-two thousand, sixty-four".