20804785 has 16 divisors (see below), whose sum is σ = 25675776. Its totient is φ = 16175808.

The previous prime is 20804783. The next prime is 20804789. The reversal of 20804785 is 58740802.

It is a cyclic number.

It is not a de Polignac number, because 20804785 - 2¹ = 20804783 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20804785.

It is not an unprimeable number, because it can be changed into a prime (20804783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52207 + ... + 52603.

It is an arithmetic number, because the mean of its divisors is an integer number (1604736).

Almost surely, 2^20804785 is an apocalyptic number.

It is an amenable number.

20804785 is a deficient number, since it is larger than the sum of its proper divisors (4870991).

20804785 is a wasteful number, since it uses less digits than its factorization.

20804785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672.

The product of its (nonzero) digits is 17920, while the sum is 34.

The square root of 20804785 is about 4561.2262605576. The cubic root of 20804785 is about 275.0348605945.

The spelling of 20804785 in words is "twenty million, eight hundred four thousand, seven hundred eighty-five".