20523109 has 4 divisors (see below), whose sum is σ = 20532204. Its totient is φ = 20514016.

The previous prime is 20523103. The next prime is 20523119. The reversal of 20523109 is 90132502.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 9132484 + 11390625 = 3022^2 + 3375^2 .

It is a cyclic number.

It is not a de Polignac number, because 20523109 - 2⁵ = 20523077 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 20523109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20523103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1689 + ... + 6625.

It is an arithmetic number, because the mean of its divisors is an integer number (5133051).

Almost surely, 2^20523109 is an apocalyptic number.

It is an amenable number.

20523109 is a deficient number, since it is larger than the sum of its proper divisors (9095).

20523109 is an equidigital number, since it uses as much as digits as its factorization.

20523109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9094.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 20523109 is about 4530.2438124233. The cubic root of 20523109 is about 273.7879839984.

The spelling of 20523109 in words is "twenty million, five hundred twenty-three thousand, one hundred nine".