21668682 has 32 divisors (see below), whose sum is σ = 50544000. Its totient is φ = 6190464.

The previous prime is 21668681. The next prime is 21668711. The reversal of 21668682 is 28686612.

It is a self number, because there is not a number n which added to its sum of digits gives 21668682.

It is not an unprimeable number, because it can be changed into a prime (21668681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3207 + ... + 7322.

It is an arithmetic number, because the mean of its divisors is an integer number (1579500).

Almost surely, 2^21668682 is an apocalyptic number.

21668682 is an abundant number, since it is smaller than the sum of its proper divisors (28875318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21668682 is a wasteful number, since it uses less digits than its factorization.

21668682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10555 (or 10541 counting only the distinct ones).

The product of its digits is 55296, while the sum is 39.

The square root of 21668682 is about 4654.9631577489. The cubic root of 21668682 is about 278.7901969688.

The spelling of 21668682 in words is "twenty-one million, six hundred sixty-eight thousand, six hundred eighty-two".