420006421 has 2 divisors, whose sum is σ = 420006422. Its totient is φ = 420006420.

The previous prime is 420006409. The next prime is 420006467. The reversal of 420006421 is 124600024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 399440196 + 20566225 = 19986^2 + 4535^2 .

It is a cyclic number.

It is not a de Polignac number, because 420006421 - 2⁹ = 420005909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420006481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210003210 + 210003211.

It is an arithmetic number, because the mean of its divisors is an integer number (210003211).

Almost surely, 2^420006421 is an apocalyptic number.

It is an amenable number.

420006421 is a deficient number, since it is larger than the sum of its proper divisors (1).

420006421 is an equidigital number, since it uses as much as digits as its factorization.

420006421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 420006421 is about 20494.0581876797. The cubic root of 420006421 is about 748.8910550555.

Adding to 420006421 its reverse (124600024), we get a palindrome (544606445).

The spelling of 420006421 in words is "four hundred twenty million, six thousand, four hundred twenty-one".