168477681 has 4 divisors (see below), whose sum is σ = 224636912. Its totient is φ = 112318452.

The previous prime is 168477677. The next prime is 168477697. The reversal of 168477681 is 186774861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 168477681 - 2² = 168477677 is a prime.

It is a super-2 number, since 2×168477681² = 56769457990275522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 168477681.

It is not an unprimeable number, because it can be changed into a prime (168477601) 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 3 ways as a sum of consecutive naturals, for example, 28079611 + ... + 28079616.

It is an arithmetic number, because the mean of its divisors is an integer number (56159228).

Almost surely, 2^168477681 is an apocalyptic number.

It is an amenable number.

168477681 is a deficient number, since it is larger than the sum of its proper divisors (56159231).

168477681 is an equidigital number, since it uses as much as digits as its factorization.

168477681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56159230.

The product of its digits is 451584, while the sum is 48.

The square root of 168477681 is about 12979.8952615189. The cubic root of 168477681 is about 552.3073108967.

The spelling of 168477681 in words is "one hundred sixty-eight million, four hundred seventy-seven thousand, six hundred eighty-one".