20559209 has 8 divisors (see below), whose sum is σ = 22736352. Its totient is φ = 18433440.

The previous prime is 20559193. The next prime is 20559223. The reversal of 20559209 is 90295502.

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 20559209 - 2⁴ = 20559193 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20559269) 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, 11999 + ... + 13604.

It is an arithmetic number, because the mean of its divisors is an integer number (2842044).

Almost surely, 2^20559209 is an apocalyptic number.

It is an amenable number.

20559209 is a deficient number, since it is larger than the sum of its proper divisors (2177143).

20559209 is a wasteful number, since it uses less digits than its factorization.

20559209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25687.

The product of its (nonzero) digits is 8100, while the sum is 32.

The square root of 20559209 is about 4534.2263948771. The cubic root of 20559209 is about 273.9484203262.

The spelling of 20559209 in words is "twenty million, five hundred fifty-nine thousand, two hundred nine".