12421434521 has 4 divisors (see below), whose sum is σ = 12427558500. Its totient is φ = 12415310544.

The previous prime is 12421434503. The next prime is 12421434577. The reversal of 12421434521 is 12543412421.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6394241296 + 6027193225 = 79964^2 + 77635^2 .

It is a cyclic number.

It is not a de Polignac number, because 12421434521 - 2⁶ = 12421434457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12421434121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3058946 + ... + 3063003.

It is an arithmetic number, because the mean of its divisors is an integer number (3106889625).

Almost surely, 2^12421434521 is an apocalyptic number.

It is an amenable number.

12421434521 is a deficient number, since it is larger than the sum of its proper divisors (6123979).

12421434521 is an equidigital number, since it uses as much as digits as its factorization.

12421434521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6123978.

The product of its digits is 7680, while the sum is 29.

Adding to 12421434521 its reverse (12543412421), we get a palindrome (24964846942).

The spelling of 12421434521 in words is "twelve billion, four hundred twenty-one million, four hundred thirty-four thousand, five hundred twenty-one".