20805716 has 12 divisors (see below), whose sum is σ = 36443988. Its totient is φ = 10393152.

The previous prime is 20805713. The next prime is 20805721. The reversal of 20805716 is 61750802.

It can be written as a sum of positive squares in 2 ways, for example, as 11195716 + 9610000 = 3346^2 + 3100^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20805713) 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, 4760 + ... + 8016.

It is an arithmetic number, because the mean of its divisors is an integer number (3036999).

Almost surely, 2^20805716 is an apocalyptic number.

It is an amenable number.

20805716 is a deficient number, since it is larger than the sum of its proper divisors (15638272).

20805716 is a wasteful number, since it uses less digits than its factorization.

20805716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4858 (or 4856 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 20805716 is about 4561.3283153047. The cubic root of 20805716 is about 275.0389630743.

The spelling of 20805716 in words is "twenty million, eight hundred five thousand, seven hundred sixteen".