18161361 has 8 divisors (see below), whose sum is σ = 26905760. Its totient is φ = 12107556.

The previous prime is 18161357. The next prime is 18161369. The reversal of 18161361 is 16316181.

It is not a de Polignac number, because 18161361 - 2² = 18161357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 672643 = 18161361 / (1 + 8 + 1 + 6 + 1 + 3 + 6 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18161369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 336295 + ... + 336348.

It is an arithmetic number, because the mean of its divisors is an integer number (3363220).

Almost surely, 2^18161361 is an apocalyptic number.

It is an amenable number.

18161361 is a deficient number, since it is larger than the sum of its proper divisors (8744399).

18161361 is an equidigital number, since it uses as much as digits as its factorization.

18161361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672652 (or 672646 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 18161361 is about 4261.6148347780. The cubic root of 18161361 is about 262.8549321170.

The spelling of 18161361 in words is "eighteen million, one hundred sixty-one thousand, three hundred sixty-one".