18191201 has 6 divisors (see below), whose sum is σ = 21161250. Its totient is φ = 15592416.

The previous prime is 18191179. The next prime is 18191213. The reversal of 18191201 is 10219181.

It can be written as a sum of positive squares in only one way, i.e., 17230801 + 960400 = 4151^2 + 980^2 .

It is not a de Polignac number, because 18191201 - 2¹⁴ = 18174817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18191221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 185576 + ... + 185673.

It is an arithmetic number, because the mean of its divisors is an integer number (3526875).

Almost surely, 2^18191201 is an apocalyptic number.

It is an amenable number.

18191201 is a deficient number, since it is larger than the sum of its proper divisors (2970049).

18191201 is an equidigital number, since it uses as much as digits as its factorization.

18191201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371263 (or 371256 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 23.

The square root of 18191201 is about 4265.1144181604. The cubic root of 18191201 is about 262.9988144925.

The spelling of 18191201 in words is "eighteen million, one hundred ninety-one thousand, two hundred one".