505406165993 has 2 divisors, whose sum is σ = 505406165994. Its totient is φ = 505406165992.

The previous prime is 505406165951. The next prime is 505406166077. The reversal of 505406165993 is 399561604505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 365647577344 + 139758588649 = 604688^2 + 373843^2 .

It is a cyclic number.

It is not a de Polignac number, because 505406165993 - 2¹⁰ = 505406164969 is a prime.

It is not a weakly prime, because it can be changed into another prime (505406165903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252703082996 + 252703082997.

It is an arithmetic number, because the mean of its divisors is an integer number (252703082997).

Almost surely, 2^505406165993 is an apocalyptic number.

It is an amenable number.

505406165993 is a deficient number, since it is larger than the sum of its proper divisors (1).

505406165993 is an equidigital number, since it uses as much as digits as its factorization.

505406165993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374000, while the sum is 53.

The spelling of 505406165993 in words is "five hundred five billion, four hundred six million, one hundred sixty-five thousand, nine hundred ninety-three".