20550559 has 4 divisors (see below), whose sum is σ = 20664280. Its totient is φ = 20436840.

The previous prime is 20550547. The next prime is 20550587. The reversal of 20550559 is 95505502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20550559 - 2¹¹ = 20548511 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 20550559.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20550529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56589 + ... + 56950.

It is an arithmetic number, because the mean of its divisors is an integer number (5166070).

Almost surely, 2^20550559 is an apocalyptic number.

20550559 is a deficient number, since it is larger than the sum of its proper divisors (113721).

20550559 is a wasteful number, since it uses less digits than its factorization.

20550559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113720.

The product of its (nonzero) digits is 11250, while the sum is 31.

The square root of 20550559 is about 4533.2724383165. The cubic root of 20550559 is about 273.9099949464.

The spelling of 20550559 in words is "twenty million, five hundred fifty thousand, five hundred fifty-nine".