12420443531 has 4 divisors (see below), whose sum is σ = 12756131232. Its totient is φ = 12084755832.

The previous prime is 12420443521. The next prime is 12420443533. The reversal of 12420443531 is 13534402421.

12420443531 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: 13534402421 = 4973 ⋅2721577.

It is a cyclic number.

It is not a de Polignac number, because 12420443531 - 2¹⁸ = 12420181387 is a prime.

It is a super-2 number, since 2×12420443531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12420443494 and 12420443503.

It is not an unprimeable number, because it can be changed into a prime (12420443533) by changing a digit.

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, 167843795 + ... + 167843868.

It is an arithmetic number, because the mean of its divisors is an integer number (3189032808).

Almost surely, 2^12420443531 is an apocalyptic number.

12420443531 is a deficient number, since it is larger than the sum of its proper divisors (335687701).

12420443531 is an equidigital number, since it uses as much as digits as its factorization.

12420443531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335687700.

The product of its (nonzero) digits is 11520, while the sum is 29.

Adding to 12420443531 its reverse (13534402421), we get a palindrome (25954845952).

The spelling of 12420443531 in words is "twelve billion, four hundred twenty million, four hundred forty-three thousand, five hundred thirty-one".