505435781 has 2 divisors, whose sum is σ = 505435782. Its totient is φ = 505435780.

The previous prime is 505435771. The next prime is 505435783. The reversal of 505435781 is 187534505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 498628900 + 6806881 = 22330^2 + 2609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-505435781 is a prime.

It is a super-2 number, since 2×505435781² = 510930657430159922, which contains 22 as substring.

Together with 505435783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505435783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252717890 + 252717891.

It is an arithmetic number, because the mean of its divisors is an integer number (252717891).

Almost surely, 2^505435781 is an apocalyptic number.

It is an amenable number.

505435781 is a deficient number, since it is larger than the sum of its proper divisors (1).

505435781 is an equidigital number, since it uses as much as digits as its factorization.

505435781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84000, while the sum is 38.

The square root of 505435781 is about 22481.8989633883. The cubic root of 505435781 is about 796.5664201829.

The spelling of 505435781 in words is "five hundred five million, four hundred thirty-five thousand, seven hundred eighty-one".