20516109 has 4 divisors (see below), whose sum is σ = 27354816. Its totient is φ = 13677404.

The previous prime is 20516107. The next prime is 20516123. The reversal of 20516109 is 90161502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20516109 - 2¹ = 20516107 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20516107) 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, 3419349 + ... + 3419354.

It is an arithmetic number, because the mean of its divisors is an integer number (6838704).

Almost surely, 2^20516109 is an apocalyptic number.

It is an amenable number.

20516109 is a deficient number, since it is larger than the sum of its proper divisors (6838707).

20516109 is an equidigital number, since it uses as much as digits as its factorization.

20516109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6838706.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 20516109 is about 4529.4711611843. The cubic root of 20516109 is about 273.7568526881.

The spelling of 20516109 in words is "twenty million, five hundred sixteen thousand, one hundred nine".