505616161 has 2 divisors, whose sum is σ = 505616162. Its totient is φ = 505616160.

The previous prime is 505616149. The next prime is 505616171. The reversal of 505616161 is 161616505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 307791936 + 197824225 = 17544^2 + 14065^2 .

It is a cyclic number.

It is not a de Polignac number, because 505616161 - 2¹¹ = 505614113 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 (505616171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252808080 + 252808081.

It is an arithmetic number, because the mean of its divisors is an integer number (252808081).

Almost surely, 2^505616161 is an apocalyptic number.

It is an amenable number.

505616161 is a deficient number, since it is larger than the sum of its proper divisors (1).

505616161 is an equidigital number, since it uses as much as digits as its factorization.

505616161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 505616161 is about 22485.9102773270. The cubic root of 505616161 is about 796.6611684951.

The spelling of 505616161 in words is "five hundred five million, six hundred sixteen thousand, one hundred sixty-one".