421021543 has 2 divisors, whose sum is σ = 421021544. Its totient is φ = 421021542.

The previous prime is 421021511. The next prime is 421021553. The reversal of 421021543 is 345120124.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 421021543 - 2⁵ = 421021511 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421021553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210510771 + 210510772.

It is an arithmetic number, because the mean of its divisors is an integer number (210510772).

Almost surely, 2^421021543 is an apocalyptic number.

421021543 is a deficient number, since it is larger than the sum of its proper divisors (1).

421021543 is an equidigital number, since it uses as much as digits as its factorization.

421021543 is an evil number, because the sum of its binary digits is even.

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

The square root of 421021543 is about 20518.8094927557. The cubic root of 421021543 is about 749.4939062727.

Adding to 421021543 its reverse (345120124), we get a palindrome (766141667).

The spelling of 421021543 in words is "four hundred twenty-one million, twenty-one thousand, five hundred forty-three".