421003421 has 2 divisors, whose sum is σ = 421003422. Its totient is φ = 421003420.

The previous prime is 421003391. The next prime is 421003423. The reversal of 421003421 is 124300124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 383964025 + 37039396 = 19595^2 + 6086^2 .

It is a cyclic number.

It is not a de Polignac number, because 421003421 - 2¹⁰ = 421002397 is a prime.

Together with 421003423, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 421003421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421003423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210501710 + 210501711.

It is an arithmetic number, because the mean of its divisors is an integer number (210501711).

Almost surely, 2^421003421 is an apocalyptic number.

It is an amenable number.

421003421 is a deficient number, since it is larger than the sum of its proper divisors (1).

421003421 is an equidigital number, since it uses as much as digits as its factorization.

421003421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 421003421 is about 20518.3678931829. The cubic root of 421003421 is about 749.4831526476.

Adding to 421003421 its reverse (124300124), we get a palindrome (545303545).

The spelling of 421003421 in words is "four hundred twenty-one million, three thousand, four hundred twenty-one".