21329689 has 8 divisors (see below), whose sum is σ = 21631680. Its totient is φ = 21030096.

The previous prime is 21329683. The next prime is 21329699. The reversal of 21329689 is 98692312.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21329689 - 2⁹ = 21329177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21329683) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 23604 + ... + 24490.

It is an arithmetic number, because the mean of its divisors is an integer number (2703960).

Almost surely, 2^21329689 is an apocalyptic number.

It is an amenable number.

21329689 is a deficient number, since it is larger than the sum of its proper divisors (301991).

21329689 is a wasteful number, since it uses less digits than its factorization.

21329689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1199.

The product of its digits is 46656, while the sum is 40.

The square root of 21329689 is about 4618.4076260114. The cubic root of 21329689 is about 277.3287160934.

The spelling of 21329689 in words is "twenty-one million, three hundred twenty-nine thousand, six hundred eighty-nine".