420551 has 2 divisors, whose sum is σ = 420552. Its totient is φ = 420550.

The previous prime is 420521. The next prime is 420557. The reversal of 420551 is 155024.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 420551 - 2¹⁰ = 419527 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420557) 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, 210275 + 210276.

It is an arithmetic number, because the mean of its divisors is an integer number (210276).

2⁴²⁰⁵⁵¹ is an apocalyptic number.

420551 is a deficient number, since it is larger than the sum of its proper divisors (1).

420551 is an equidigital number, since it uses as much as digits as its factorization.

420551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 420551 is about 648.4990362368. The cubic root of 420551 is about 74.9214585193.

Adding to 420551 its reverse (155024), we get a palindrome (575575).

The spelling of 420551 in words is "four hundred twenty thousand, five hundred fifty-one".