21329188 has 12 divisors (see below), whose sum is σ = 38949120. Its totient is φ = 10200872.

The previous prime is 21329177. The next prime is 21329207. The reversal of 21329188 is 88192312.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 115828 + ... + 116011.

It is an arithmetic number, because the mean of its divisors is an integer number (3245760).

Almost surely, 2^21329188 is an apocalyptic number.

It is an amenable number.

21329188 is a deficient number, since it is larger than the sum of its proper divisors (17619932).

21329188 is a wasteful number, since it uses less digits than its factorization.

21329188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231866 (or 231864 counting only the distinct ones).

The product of its digits is 6912, while the sum is 34.

The square root of 21329188 is about 4618.3533862189. The cubic root of 21329188 is about 277.3265447416.

The spelling of 21329188 in words is "twenty-one million, three hundred twenty-nine thousand, one hundred eighty-eight".