20806568 has 8 divisors (see below), whose sum is σ = 39012330. Its totient is φ = 10403280.

The previous prime is 20806561. The next prime is 20806573. The reversal of 20806568 is 86560802.

It can be written as a sum of positive squares in only one way, i.e., 20232004 + 574564 = 4498^2 + 758^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (20806561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1300403 + ... + 1300418.

Almost surely, 2^20806568 is an apocalyptic number.

It is an amenable number.

20806568 is a deficient number, since it is larger than the sum of its proper divisors (18205762).

20806568 is a wasteful number, since it uses less digits than its factorization.

20806568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2600827 (or 2600823 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 20806568 is about 4561.4217081958. The cubic root of 20806568 is about 275.0427173311.

The spelling of 20806568 in words is "twenty million, eight hundred six thousand, five hundred sixty-eight".