21606308 has 12 divisors (see below), whose sum is σ = 37844352. Its totient is φ = 10793640.

The previous prime is 21606289. The next prime is 21606313. The reversal of 21606308 is 80360612.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6041 + ... + 8927.

It is an arithmetic number, because the mean of its divisors is an integer number (3153696).

Almost surely, 2^21606308 is an apocalyptic number.

It is an amenable number.

21606308 is a deficient number, since it is larger than the sum of its proper divisors (16238044).

21606308 is a wasteful number, since it uses less digits than its factorization.

21606308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4762 (or 4760 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 21606308 is about 4648.2585986582. The cubic root of 21606308 is about 278.5224376951.

The spelling of 21606308 in words is "twenty-one million, six hundred six thousand, three hundred eight".