20708665 has 16 divisors (see below), whose sum is σ = 25459200. Its totient is φ = 16166592.

The previous prime is 20708663. The next prime is 20708693. The reversal of 20708665 is 56680702.

It is a cyclic number.

It is not a de Polignac number, because 20708665 - 2¹ = 20708663 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20708665.

It is not an unprimeable number, because it can be changed into a prime (20708663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40431 + ... + 40939.

It is an arithmetic number, because the mean of its divisors is an integer number (1591200).

Almost surely, 2^20708665 is an apocalyptic number.

It is an amenable number.

20708665 is a deficient number, since it is larger than the sum of its proper divisors (4750535).

20708665 is a wasteful number, since it uses less digits than its factorization.

20708665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 20708665 is about 4550.6774220988. The cubic root of 20708665 is about 274.6106445883.

The spelling of 20708665 in words is "twenty million, seven hundred eight thousand, six hundred sixty-five".