20563289 has 4 divisors (see below), whose sum is σ = 20713524. Its totient is φ = 20413056.

The previous prime is 20563259. The next prime is 20563307. The reversal of 20563289 is 98236502.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10272025 + 10291264 = 3205^2 + 3208^2 .

It is a cyclic number.

It is not a de Polignac number, because 20563289 - 2¹² = 20559193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20563259) 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 3 ways as a sum of consecutive naturals, for example, 74912 + ... + 75185.

It is an arithmetic number, because the mean of its divisors is an integer number (5178381).

Almost surely, 2^20563289 is an apocalyptic number.

It is an amenable number.

20563289 is a deficient number, since it is larger than the sum of its proper divisors (150235).

20563289 is a wasteful number, since it uses less digits than its factorization.

20563289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150234.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 20563289 is about 4534.6762839259. The cubic root of 20563289 is about 273.9665409265.

The spelling of 20563289 in words is "twenty million, five hundred sixty-three thousand, two hundred eighty-nine".