20109563 has 4 divisors (see below), whose sum is σ = 20211840. Its totient is φ = 20007288.

The previous prime is 20109553. The next prime is 20109577. The reversal of 20109563 is 36590102.

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 20109563 - 2¹⁴ = 20093179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20109503) 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, 50843 + ... + 51236.

It is an arithmetic number, because the mean of its divisors is an integer number (5052960).

Almost surely, 2^20109563 is an apocalyptic number.

20109563 is a deficient number, since it is larger than the sum of its proper divisors (102277).

20109563 is a wasteful number, since it uses less digits than its factorization.

20109563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102276.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 20109563 is about 4484.3687404137. The cubic root of 20109563 is about 271.9365255217.

Adding to 20109563 its reverse (36590102), we get a palindrome (56699665).

The spelling of 20109563 in words is "twenty million, one hundred nine thousand, five hundred sixty-three".