12121404520 has 32 divisors (see below), whose sum is σ = 27301163400. Its totient is φ = 4843583488.

The previous prime is 12121404509. The next prime is 12121404527. The reversal of 12121404520 is 2540412121.

It can be written as a sum of positive squares in 4 ways, for example, as 11656657156 + 464747364 = 107966^2 + 21558^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12121404491 and 12121404500.

It is not an unprimeable number, because it can be changed into a prime (12121404527) 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 7 ways as a sum of consecutive naturals, for example, 116005 + ... + 194164.

Almost surely, 2^12121404520 is an apocalyptic number.

12121404520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12121404520 is an abundant number, since it is smaller than the sum of its proper divisors (15179758880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12121404520 is a wasteful number, since it uses less digits than its factorization.

12121404520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311157 (or 311153 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

Adding to 12121404520 its reverse (2540412121), we get a palindrome (14661816641).

The spelling of 12121404520 in words is "twelve billion, one hundred twenty-one million, four hundred four thousand, five hundred twenty".