20012518109 has 4 divisors (see below), whose sum is σ = 20882627616. Its totient is φ = 19142408604.

The previous prime is 20012518081. The next prime is 20012518117. The reversal of 20012518109 is 90181521002.

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 20012518109 - 2²⁴ = 19995740893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20012511109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 435054719 + ... + 435054764.

It is an arithmetic number, because the mean of its divisors is an integer number (5220656904).

Almost surely, 2^20012518109 is an apocalyptic number.

It is an amenable number.

20012518109 is a deficient number, since it is larger than the sum of its proper divisors (870109507).

20012518109 is an equidigital number, since it uses as much as digits as its factorization.

20012518109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870109506.

The product of its (nonzero) digits is 1440, while the sum is 29.

The spelling of 20012518109 in words is "twenty billion, twelve million, five hundred eighteen thousand, one hundred nine".