505305552781 has 2 divisors, whose sum is σ = 505305552782. Its totient is φ = 505305552780.

The previous prime is 505305552737. The next prime is 505305552793. The reversal of 505305552781 is 187255503505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 463442346756 + 41863206025 = 680766^2 + 204605^2 .

It is a cyclic number.

It is not a de Polignac number, because 505305552781 - 2³⁵ = 470945814413 is a prime.

It is a super-2 number, since 2×505305552781² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505305562781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252652776390 + 252652776391.

It is an arithmetic number, because the mean of its divisors is an integer number (252652776391).

Almost surely, 2^505305552781 is an apocalyptic number.

It is an amenable number.

505305552781 is a deficient number, since it is larger than the sum of its proper divisors (1).

505305552781 is an equidigital number, since it uses as much as digits as its factorization.

505305552781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1050000, while the sum is 46.

The spelling of 505305552781 in words is "five hundred five billion, three hundred five million, five hundred fifty-two thousand, seven hundred eighty-one".