421433021 has 2 divisors, whose sum is σ = 421433022. Its totient is φ = 421433020.

The previous prime is 421433011. The next prime is 421433027. The reversal of 421433021 is 120334124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214476025 + 206956996 = 14645^2 + 14386^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421433021 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 421432984 and 421433002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421433027) 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 as a sum of consecutive naturals, namely, 210716510 + 210716511.

It is an arithmetic number, because the mean of its divisors is an integer number (210716511).

Almost surely, 2^421433021 is an apocalyptic number.

It is an amenable number.

421433021 is a deficient number, since it is larger than the sum of its proper divisors (1).

421433021 is an equidigital number, since it uses as much as digits as its factorization.

421433021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 421433021 is about 20528.8338928445. The cubic root of 421433021 is about 749.7379950004.

Adding to 421433021 its reverse (120334124), we get a palindrome (541767145).

The spelling of 421433021 in words is "four hundred twenty-one million, four hundred thirty-three thousand, twenty-one".