420423217 has 2 divisors, whose sum is σ = 420423218. Its totient is φ = 420423216.

The previous prime is 420423181. The next prime is 420423229. The reversal of 420423217 is 712324024.

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., 325477681 + 94945536 = 18041^2 + 9744^2 .

It is a cyclic number.

It is not a de Polignac number, because 420423217 - 2¹⁵ = 420390449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 420423191 and 420423200.

It is not a weakly prime, because it can be changed into another prime (420423247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210211608 + 210211609.

It is an arithmetic number, because the mean of its divisors is an integer number (210211609).

Almost surely, 2^420423217 is an apocalyptic number.

It is an amenable number.

420423217 is a deficient number, since it is larger than the sum of its proper divisors (1).

420423217 is an equidigital number, since it uses as much as digits as its factorization.

420423217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 420423217 is about 20504.2243696269. The cubic root of 420423217 is about 749.1386953993.

The spelling of 420423217 in words is "four hundred twenty million, four hundred twenty-three thousand, two hundred seventeen".