20804865 has 8 divisors (see below), whose sum is σ = 33287808. Its totient is φ = 11095920.

The previous prime is 20804837. The next prime is 20804869. The reversal of 20804865 is 56840802.

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

It is not a de Polignac number, because 20804865 - 2⁷ = 20804737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20804869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 693481 + ... + 693510.

It is an arithmetic number, because the mean of its divisors is an integer number (4160976).

Almost surely, 2^20804865 is an apocalyptic number.

It is an amenable number.

20804865 is a deficient number, since it is larger than the sum of its proper divisors (12482943).

20804865 is a wasteful number, since it uses less digits than its factorization.

20804865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1386999.

The product of its (nonzero) digits is 15360, while the sum is 33.

The square root of 20804865 is about 4561.2350301207. The cubic root of 20804865 is about 275.0352131217.

The spelling of 20804865 in words is "twenty million, eight hundred four thousand, eight hundred sixty-five".