420335521 has 2 divisors, whose sum is σ = 420335522. Its totient is φ = 420335520.

The previous prime is 420335507. The next prime is 420335543. The reversal of 420335521 is 125533024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 311028496 + 109307025 = 17636^2 + 10455^2 .

It is a cyclic number.

It is not a de Polignac number, because 420335521 - 2¹⁹ = 419811233 is a prime.

It is not a weakly prime, because it can be changed into another prime (420335581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210167760 + 210167761.

It is an arithmetic number, because the mean of its divisors is an integer number (210167761).

Almost surely, 2^420335521 is an apocalyptic number.

It is an amenable number.

420335521 is a deficient number, since it is larger than the sum of its proper divisors (1).

420335521 is an equidigital number, since it uses as much as digits as its factorization.

420335521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 25.

The square root of 420335521 is about 20502.0857719404. The cubic root of 420335521 is about 749.0866042106.

Adding to 420335521 its reverse (125533024), we get a palindrome (545868545).

The spelling of 420335521 in words is "four hundred twenty million, three hundred thirty-five thousand, five hundred twenty-one".