605420021 has 2 divisors, whose sum is σ = 605420022. Its totient is φ = 605420020.

The previous prime is 605420003. The next prime is 605420027. The reversal of 605420021 is 120024506.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 440580100 + 164839921 = 20990^2 + 12839^2 .

It is a cyclic number.

It is not a de Polignac number, because 605420021 - 2²⁶ = 538311157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 605419975 and 605420002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (605420027) 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, 302710010 + 302710011.

It is an arithmetic number, because the mean of its divisors is an integer number (302710011).

Almost surely, 2^605420021 is an apocalyptic number.

It is an amenable number.

605420021 is a deficient number, since it is larger than the sum of its proper divisors (1).

605420021 is an equidigital number, since it uses as much as digits as its factorization.

605420021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 605420021 is about 24605.2844120933. The cubic root of 605420021 is about 845.9647354741.

Adding to 605420021 its reverse (120024506), we get a palindrome (725444527).

The spelling of 605420021 in words is "six hundred five million, four hundred twenty thousand, twenty-one".