20908665 has 32 divisors (see below), whose sum is σ = 37795200. Its totient is φ = 10964160.

The previous prime is 20908651. The next prime is 20908669. The reversal of 20908665 is 56680902.

It is not a de Polignac number, because 20908665 - 2⁴ = 20908649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20908669) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6966 + ... + 9504.

It is an arithmetic number, because the mean of its divisors is an integer number (1181100).

Almost surely, 2^20908665 is an apocalyptic number.

It is an amenable number.

20908665 is a deficient number, since it is larger than the sum of its proper divisors (16886535).

20908665 is a wasteful number, since it uses less digits than its factorization.

20908665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2614 (or 2608 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 20908665 is about 4572.5993701614. The cubic root of 20908665 is about 275.4918580427.

The spelling of 20908665 in words is "twenty million, nine hundred eight thousand, six hundred sixty-five".