168388505 has 8 divisors (see below), whose sum is σ = 202511112. Its totient is φ = 134414208.

The previous prime is 168388501. The next prime is 168388511. The reversal of 168388505 is 505883861.

It can be written as a sum of positive squares in 4 ways, for example, as 31685641 + 136702864 = 5629^2 + 11692^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 168388505 - 2² = 168388501 is a prime.

It is a super-2 number, since 2×168388505² = 56709377232270050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168388501) 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 in 7 ways as a sum of consecutive naturals, for example, 34562 + ... + 39131.

It is an arithmetic number, because the mean of its divisors is an integer number (25313889).

Almost surely, 2^168388505 is an apocalyptic number.

It is an amenable number.

168388505 is a deficient number, since it is larger than the sum of its proper divisors (34122607).

168388505 is an equidigital number, since it uses as much as digits as its factorization.

168388505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74155.

The product of its (nonzero) digits is 230400, while the sum is 44.

The square root of 168388505 is about 12976.4596481475. The cubic root of 168388505 is about 552.2098474445.

The spelling of 168388505 in words is "one hundred sixty-eight million, three hundred eighty-eight thousand, five hundred five".