420405551 has 2 divisors, whose sum is σ = 420405552. Its totient is φ = 420405550.

The previous prime is 420405527. The next prime is 420405577. The reversal of 420405551 is 155504024.

It is an a-pointer prime, because the next prime (420405577) can be obtained adding 420405551 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420405551 is a prime.

It is a super-2 number, since 2×420405551² = 353481654623227202, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 420405551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420405511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210202775 + 210202776.

It is an arithmetic number, because the mean of its divisors is an integer number (210202776).

Almost surely, 2^420405551 is an apocalyptic number.

420405551 is a deficient number, since it is larger than the sum of its proper divisors (1).

420405551 is an equidigital number, since it uses as much as digits as its factorization.

420405551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 420405551 is about 20503.7935758240. The cubic root of 420405551 is about 749.1282024254.

Adding to 420405551 its reverse (155504024), we get a palindrome (575909575).

The spelling of 420405551 in words is "four hundred twenty million, four hundred five thousand, five hundred fifty-one".