505638761 has 2 divisors, whose sum is σ = 505638762. Its totient is φ = 505638760.

The previous prime is 505638713. The next prime is 505638823. The reversal of 505638761 is 167836505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 499969600 + 5669161 = 22360^2 + 2381^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-505638761 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (505638061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252819380 + 252819381.

It is an arithmetic number, because the mean of its divisors is an integer number (252819381).

Almost surely, 2^505638761 is an apocalyptic number.

It is an amenable number.

505638761 is a deficient number, since it is larger than the sum of its proper divisors (1).

505638761 is an equidigital number, since it uses as much as digits as its factorization.

505638761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 151200, while the sum is 41.

The square root of 505638761 is about 22486.4128086273. The cubic root of 505638761 is about 796.6730380222.

The spelling of 505638761 in words is "five hundred five million, six hundred thirty-eight thousand, seven hundred sixty-one".