21688868504 has 16 divisors (see below), whose sum is σ = 40668342000. Its totient is φ = 10843977312.

The previous prime is 21688868479. The next prime is 21688868557. The reversal of 21688868504 is 40586888612.

It is a self number, because there is not a number n which added to its sum of digits gives 21688868504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 228797 + ... + 309395.

It is an arithmetic number, because the mean of its divisors is an integer number (2541771375).

Almost surely, 2^21688868504 is an apocalyptic number.

It is an amenable number.

21688868504 is a deficient number, since it is larger than the sum of its proper divisors (18979473496).

21688868504 is a wasteful number, since it uses less digits than its factorization.

21688868504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114242 (or 114238 counting only the distinct ones).

The product of its (nonzero) digits is 5898240, while the sum is 56.

The spelling of 21688868504 in words is "twenty-one billion, six hundred eighty-eight million, eight hundred sixty-eight thousand, five hundred four".