20559500 has 48 divisors (see below), whose sum is σ = 48371232. Its totient is φ = 7588800.

The previous prime is 20559449. The next prime is 20559503. The reversal of 20559500 is 595502.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 20559500.

It is not an unprimeable number, because it can be changed into a prime (20559503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4919 + ... + 8081.

It is an arithmetic number, because the mean of its divisors is an integer number (1007734).

Almost surely, 2^20559500 is an apocalyptic number.

20559500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20559500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24185616).

20559500 is an abundant number, since it is smaller than the sum of its proper divisors (27811732).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20559500 is a wasteful number, since it uses less digits than its factorization.

20559500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3195 (or 3183 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 20559500 is about 4534.2584840302. The cubic root of 20559500 is about 273.9497128308.

The spelling of 20559500 in words is "twenty million, five hundred fifty-nine thousand, five hundred".