505131813 has 6 divisors (see below), whose sum is σ = 729634854. Its totient is φ = 336754536.

The previous prime is 505131811. The next prime is 505131841. The reversal of 505131813 is 318131505.

It can be written as a sum of positive squares in only one way, i.e., 339185889 + 165945924 = 18417^2 + 12882^2 .

It is not a de Polignac number, because 505131813 - 2¹ = 505131811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505131811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28062870 + ... + 28062887.

It is an arithmetic number, because the mean of its divisors is an integer number (121605809).

Almost surely, 2^505131813 is an apocalyptic number.

It is an amenable number.

505131813 is a deficient number, since it is larger than the sum of its proper divisors (224503041).

505131813 is a wasteful number, since it uses less digits than its factorization.

505131813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56125763 (or 56125760 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 505131813 is about 22475.1376636496. The cubic root of 505131813 is about 796.4067037126.

It can be divided in two parts, 50513 and 1813, that added together give a triangular number (52326 = T₃₂₃).

The spelling of 505131813 in words is "five hundred five million, one hundred thirty-one thousand, eight hundred thirteen".