20908646 has 8 divisors (see below), whose sum is σ = 34214184. Its totient is φ = 9503920.

The previous prime is 20908639. The next prime is 20908649. The reversal of 20908646 is 64680902.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20908649) 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 3 ways as a sum of consecutive naturals, for example, 475175 + ... + 475218.

It is an arithmetic number, because the mean of its divisors is an integer number (4276773).

Almost surely, 2^20908646 is an apocalyptic number.

20908646 is a deficient number, since it is larger than the sum of its proper divisors (13305538).

20908646 is a wasteful number, since it uses less digits than its factorization.

20908646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950406.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 20908646 is about 4572.5972925680. The cubic root of 20908646 is about 275.4917745949.

The spelling of 20908646 in words is "twenty million, nine hundred eight thousand, six hundred forty-six".