20911908 has 12 divisors (see below), whose sum is σ = 48794480. Its totient is φ = 6970632.

The previous prime is 20911883. The next prime is 20911909. The reversal of 20911908 is 80911902.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (20911909) 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, 871318 + ... + 871341.

Almost surely, 2^20911908 is an apocalyptic number.

It is an amenable number.

20911908 is an abundant number, since it is smaller than the sum of its proper divisors (27882572).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20911908 is a wasteful number, since it uses less digits than its factorization.

20911908 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742666 (or 1742664 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 20911908 is about 4572.9539687165. The cubic root of 20911908 is about 275.5061005255.

The spelling of 20911908 in words is "twenty million, nine hundred eleven thousand, nine hundred eight".