21170908 has 12 divisors (see below), whose sum is σ = 40417272. Its totient is φ = 9623120.

The previous prime is 21170887. The next prime is 21170909. The reversal of 21170908 is 80907112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21170909) 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 3 ways as a sum of consecutive naturals, for example, 240535 + ... + 240622.

It is an arithmetic number, because the mean of its divisors is an integer number (3368106).

Almost surely, 2^21170908 is an apocalyptic number.

It is an amenable number.

21170908 is a deficient number, since it is larger than the sum of its proper divisors (19246364).

21170908 is a wasteful number, since it uses less digits than its factorization.

21170908 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481172 (or 481170 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 21170908 is about 4601.1854994121. The cubic root of 21170908 is about 276.6388443176.

The spelling of 21170908 in words is "twenty-one million, one hundred seventy thousand, nine hundred eight".