420021803 has 2 divisors, whose sum is σ = 420021804. Its totient is φ = 420021802.

The previous prime is 420021793. The next prime is 420021827. The reversal of 420021803 is 308120024.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 420021803 - 2⁴ = 420021787 is a prime.

It is not a weakly prime, because it can be changed into another prime (420021853) 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, 210010901 + 210010902.

It is an arithmetic number, because the mean of its divisors is an integer number (210010902).

Almost surely, 2^420021803 is an apocalyptic number.

420021803 is a deficient number, since it is larger than the sum of its proper divisors (1).

420021803 is an equidigital number, since it uses as much as digits as its factorization.

420021803 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 20.

The square root of 420021803 is about 20494.4334637482. The cubic root of 420021803 is about 748.9001972186.

Adding to 420021803 its reverse (308120024), we get a palindrome (728141827).

The spelling of 420021803 in words is "four hundred twenty million, twenty-one thousand, eight hundred three".