20716805 has 8 divisors (see below), whose sum is σ = 25093152. Its totient is φ = 16418128.

The previous prime is 20716789. The next prime is 20716873. The reversal of 20716805 is 50861702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20716805 - 2⁴ = 20716789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18827 + ... + 19896.

It is an arithmetic number, because the mean of its divisors is an integer number (3136644).

Almost surely, 2^20716805 is an apocalyptic number.

It is an amenable number.

20716805 is a deficient number, since it is larger than the sum of its proper divisors (4376347).

20716805 is a wasteful number, since it uses less digits than its factorization.

20716805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38835.

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

The square root of 20716805 is about 4551.5717065647. The cubic root of 20716805 is about 274.6466204762.

The spelling of 20716805 in words is "twenty million, seven hundred sixteen thousand, eight hundred five".