163974809 has 4 divisors (see below), whose sum is σ = 173620404. Its totient is φ = 154329216.

The previous prime is 163974803. The next prime is 163974817. The reversal of 163974809 is 908479361.

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 122655625 + 41319184 = 11075^2 + 6428^2 .

It is a cyclic number.

It is not a de Polignac number, because 163974809 - 2²⁰ = 162926233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163974803) 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, 4822772 + ... + 4822805.

It is an arithmetic number, because the mean of its divisors is an integer number (43405101).

Almost surely, 2^163974809 is an apocalyptic number.

It is an amenable number.

163974809 is a deficient number, since it is larger than the sum of its proper divisors (9645595).

163974809 is an equidigital number, since it uses as much as digits as its factorization.

163974809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9645594.

The product of its (nonzero) digits is 326592, while the sum is 47.

The square root of 163974809 is about 12805.2648937849. The cubic root of 163974809 is about 547.3423400144.

The spelling of 163974809 in words is "one hundred sixty-three million, nine hundred seventy-four thousand, eight hundred nine".