18809161 has 4 divisors (see below), whose sum is σ = 21496192. Its totient is φ = 16122132.

The previous prime is 18809159. The next prime is 18809177. The reversal of 18809161 is 16190881.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16190881 = 7 ⋅2312983.

It is a cyclic number.

It is not a de Polignac number, because 18809161 - 2¹ = 18809159 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18809761) 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, 1343505 + ... + 1343518.

It is an arithmetic number, because the mean of its divisors is an integer number (5374048).

Almost surely, 2^18809161 is an apocalyptic number.

It is an amenable number.

18809161 is a deficient number, since it is larger than the sum of its proper divisors (2687031).

18809161 is an equidigital number, since it uses as much as digits as its factorization.

18809161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2687030.

The product of its (nonzero) digits is 3456, while the sum is 34.

The square root of 18809161 is about 4336.9529626225. The cubic root of 18809161 is about 265.9437620194.

The spelling of 18809161 in words is "eighteen million, eight hundred nine thousand, one hundred sixty-one".