420145421 has 2 divisors, whose sum is σ = 420145422. Its totient is φ = 420145420.

The previous prime is 420145403. The next prime is 420145477. The reversal of 420145421 is 124541024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 419676196 + 469225 = 20486^2 + 685^2 .

It is a cyclic number.

It is not a de Polignac number, because 420145421 - 2⁶ = 420145357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420145721) 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, 210072710 + 210072711.

It is an arithmetic number, because the mean of its divisors is an integer number (210072711).

Almost surely, 2^420145421 is an apocalyptic number.

It is an amenable number.

420145421 is a deficient number, since it is larger than the sum of its proper divisors (1).

420145421 is an equidigital number, since it uses as much as digits as its factorization.

420145421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 420145421 is about 20497.4491339776. The cubic root of 420145421 is about 748.9736604398.

Adding to 420145421 its reverse (124541024), we get a palindrome (544686445).

The spelling of 420145421 in words is "four hundred twenty million, one hundred forty-five thousand, four hundred twenty-one".