421543 has 4 divisors (see below), whose sum is σ = 430560. Its totient is φ = 412528.

The previous prime is 421517. The next prime is 421559. The reversal of 421543 is 345124.

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

It is a cyclic number.

It is not a de Polignac number, because 421543 - 2¹⁷ = 290471 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 421543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421643) 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, 4438 + ... + 4531.

It is an arithmetic number, because the mean of its divisors is an integer number (107640).

2⁴²¹⁵⁴³ is an apocalyptic number.

421543 is a deficient number, since it is larger than the sum of its proper divisors (9017).

421543 is an equidigital number, since it uses as much as digits as its factorization.

421543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9016.

The product of its digits is 480, while the sum is 19.

The square root of 421543 is about 649.2634288176. The cubic root of 421543 is about 74.9803207627.

Adding to 421543 its reverse (345124), we get a palindrome (766667).

The spelling of 421543 in words is "four hundred twenty-one thousand, five hundred forty-three".