12421543 has 4 divisors (see below), whose sum is σ = 13152240. Its totient is φ = 11690848.

The previous prime is 12421537. The next prime is 12421553. The reversal of 12421543 is 34512421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34512421 = 1063 ⋅32467.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12421543 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12421553) 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, 365323 + ... + 365356.

It is an arithmetic number, because the mean of its divisors is an integer number (3288060).

Almost surely, 2^12421543 is an apocalyptic number.

12421543 is a deficient number, since it is larger than the sum of its proper divisors (730697).

12421543 is an equidigital number, since it uses as much as digits as its factorization.

12421543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 730696.

The product of its digits is 960, while the sum is 22.

The square root of 12421543 is about 3524.4209453469. The cubic root of 12421543 is about 231.5928687414.

Adding to 12421543 its reverse (34512421), we get a palindrome (46933964).

The spelling of 12421543 in words is "twelve million, four hundred twenty-one thousand, five hundred forty-three".