168181969 has 4 divisors (see below), whose sum is σ = 178075044. Its totient is φ = 158288896.

The previous prime is 168181967. The next prime is 168182023. The reversal of 168181969 is 969181861.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 111028369 + 57153600 = 10537^2 + 7560^2 .

It is a cyclic number.

It is not a de Polignac number, because 168181969 - 2¹ = 168181967 is a prime.

It is a super-2 number, since 2×168181969² = 56570349393433922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168181961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4946512 + ... + 4946545.

It is an arithmetic number, because the mean of its divisors is an integer number (44518761).

Almost surely, 2^168181969 is an apocalyptic number.

It is an amenable number.

168181969 is a deficient number, since it is larger than the sum of its proper divisors (9893075).

168181969 is an equidigital number, since it uses as much as digits as its factorization.

168181969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9893074.

The product of its digits is 186624, while the sum is 49.

The square root of 168181969 is about 12968.4991035971. The cubic root of 168181969 is about 551.9839850864.

The spelling of 168181969 in words is "one hundred sixty-eight million, one hundred eighty-one thousand, nine hundred sixty-nine".