12121212523 has 4 divisors (see below), whose sum is σ = 13852814320. Its totient is φ = 10389610728.

The previous prime is 12121212503. The next prime is 12121212529. The reversal of 12121212523 is 32521212121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32521212121 = 26189 ⋅1241789.

It is not a de Polignac number, because 12121212523 - 2¹³ = 12121204331 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121212494 and 12121212503.

It is not an unprimeable number, because it can be changed into a prime (12121212529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 865800888 + ... + 865800901.

It is an arithmetic number, because the mean of its divisors is an integer number (3463203580).

Almost surely, 2^12121212523 is an apocalyptic number.

12121212523 is a deficient number, since it is larger than the sum of its proper divisors (1731601797).

12121212523 is an equidigital number, since it uses as much as digits as its factorization.

12121212523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1731601796.

The product of its digits is 480, while the sum is 22.

Adding to 12121212523 its reverse (32521212121), we get a palindrome (44642424644).

The spelling of 12121212523 in words is "twelve billion, one hundred twenty-one million, two hundred twelve thousand, five hundred twenty-three".