12506421165 has 48 divisors (see below), whose sum is σ = 23288591232. Its totient is φ = 5714438016.

The previous prime is 12506421163. The next prime is 12506421173. The reversal of 12506421165 is 56112460521.

It is not a de Polignac number, because 12506421165 - 2¹ = 12506421163 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12506421163) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2766487 + ... + 2771003.

It is an arithmetic number, because the mean of its divisors is an integer number (485178984).

Almost surely, 2^12506421165 is an apocalyptic number.

12506421165 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12506421165 is a deficient number, since it is larger than the sum of its proper divisors (10782170067).

12506421165 is a wasteful number, since it uses less digits than its factorization.

12506421165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8306 (or 8299 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

Adding to 12506421165 its reverse (56112460521), we get a palindrome (68618881686).

The spelling of 12506421165 in words is "twelve billion, five hundred six million, four hundred twenty-one thousand, one hundred sixty-five".