420021073 has 2 divisors, whose sum is σ = 420021074. Its totient is φ = 420021072.

The previous prime is 420021071. The next prime is 420021089. The reversal of 420021073 is 370120024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 394538769 + 25482304 = 19863^2 + 5048^2 .

It is a cyclic number.

It is not a de Polignac number, because 420021073 - 2¹ = 420021071 is a prime.

Together with 420021071, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 420021073.

It is not a weakly prime, because it can be changed into another prime (420021071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210010536 + 210010537.

It is an arithmetic number, because the mean of its divisors is an integer number (210010537).

Almost surely, 2^420021073 is an apocalyptic number.

It is an amenable number.

420021073 is a deficient number, since it is larger than the sum of its proper divisors (1).

420021073 is an equidigital number, since it uses as much as digits as its factorization.

420021073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 420021073 is about 20494.4156540263. The cubic root of 420021073 is about 748.8997633543.

Adding to 420021073 its reverse (370120024), we get a palindrome (790141097).

The spelling of 420021073 in words is "four hundred twenty million, twenty-one thousand, seventy-three".