505661166505 has 24 divisors (see below), whose sum is σ = 667254454272. Its totient is φ = 367597428000.

The previous prime is 505661166487. The next prime is 505661166589.

505661166505 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 505661166505 - 2⁹ = 505661165993 is a prime.

It is a super-2 number, since 2×505661166505² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1258200 + ... + 1610710.

It is an arithmetic number, because the mean of its divisors is an integer number (27802268928).

Almost surely, 2^505661166505 is an apocalyptic number.

505661166505 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

505661166505 is a deficient number, since it is larger than the sum of its proper divisors (161593287767).

505661166505 is a wasteful number, since it uses less digits than its factorization.

505661166505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354909 (or 354898 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 46.

The spelling of 505661166505 in words is "five hundred five billion, six hundred sixty-one million, one hundred sixty-six thousand, five hundred five".