21006682 has 16 divisors (see below), whose sum is σ = 33007680. Its totient is φ = 10007712.

The previous prime is 21006673. The next prime is 21006683. The reversal of 21006682 is 28660012.

It is not an unprimeable number, because it can be changed into a prime (21006683) 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, 13669 + ... + 15127.

It is an arithmetic number, because the mean of its divisors is an integer number (2062980).

Almost surely, 2^21006682 is an apocalyptic number.

21006682 is a deficient number, since it is larger than the sum of its proper divisors (12000998).

21006682 is a wasteful number, since it uses less digits than its factorization.

21006682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1797.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 21006682 is about 4583.3047029409. The cubic root of 21006682 is about 275.9216766483.

Adding to 21006682 its reverse (28660012), we get a palindrome (49666694).

The spelling of 21006682 in words is "twenty-one million, six thousand, six hundred eighty-two".