12521423155 has 4 divisors (see below), whose sum is σ = 15025707792. Its totient is φ = 10017138520.

The previous prime is 12521423147. The next prime is 12521423179. The reversal of 12521423155 is 55132412521.

12521423155 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55132412521 = 2887 ⋅19096783.

It is not a de Polignac number, because 12521423155 - 2³ = 12521423147 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1252142311 + ... + 1252142320.

It is an arithmetic number, because the mean of its divisors is an integer number (3756426948).

Almost surely, 2^12521423155 is an apocalyptic number.

12521423155 is a deficient number, since it is larger than the sum of its proper divisors (2504284637).

12521423155 is an equidigital number, since it uses as much as digits as its factorization.

12521423155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2504284636.

The product of its digits is 12000, while the sum is 31.

Adding to 12521423155 its reverse (55132412521), we get a palindrome (67653835676).

The spelling of 12521423155 in words is "twelve billion, five hundred twenty-one million, four hundred twenty-three thousand, one hundred fifty-five".