21688682 has 8 divisors (see below), whose sum is σ = 32563296. Its totient is φ = 10834252.

The previous prime is 21688669. The next prime is 21688699. The reversal of 21688682 is 28688612.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1988 + ... + 6879.

It is an arithmetic number, because the mean of its divisors is an integer number (4070412).

Almost surely, 2^21688682 is an apocalyptic number.

21688682 is a deficient number, since it is larger than the sum of its proper divisors (10874614).

21688682 is a wasteful number, since it uses less digits than its factorization.

21688682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10092.

The product of its digits is 73728, while the sum is 41.

The square root of 21688682 is about 4657.1109069894. The cubic root of 21688682 is about 278.8759442137.

The spelling of 21688682 in words is "twenty-one million, six hundred eighty-eight thousand, six hundred eighty-two".