505418021 has 2 divisors, whose sum is σ = 505418022. Its totient is φ = 505418020.

The previous prime is 505417967. The next prime is 505418027. The reversal of 505418021 is 120814505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 471324100 + 34093921 = 21710^2 + 5839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-505418021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505418027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252709010 + 252709011.

It is an arithmetic number, because the mean of its divisors is an integer number (252709011).

Almost surely, 2^505418021 is an apocalyptic number.

It is an amenable number.

505418021 is a deficient number, since it is larger than the sum of its proper divisors (1).

505418021 is an equidigital number, since it uses as much as digits as its factorization.

505418021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 505418021 is about 22481.5039754906. The cubic root of 505418021 is about 796.5570901580.

The spelling of 505418021 in words is "five hundred five million, four hundred eighteen thousand, twenty-one".