20205805 has 8 divisors (see below), whose sum is σ = 24274944. Its totient is φ = 16146000.

The previous prime is 20205781. The next prime is 20205821. The reversal of 20205805 is 50850202.

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

It is not a de Polignac number, because 20205805 - 2¹³ = 20197613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4000 + ... + 7510.

It is an arithmetic number, because the mean of its divisors is an integer number (3034368).

Almost surely, 2^20205805 is an apocalyptic number.

It is an amenable number.

20205805 is a deficient number, since it is larger than the sum of its proper divisors (4069139).

20205805 is a wasteful number, since it uses less digits than its factorization.

20205805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4667.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 20205805 is about 4495.0867622327. The cubic root of 20205805 is about 272.3696540149.

The spelling of 20205805 in words is "twenty million, two hundred five thousand, eight hundred five".