2009181 has 8 divisors (see below), whose sum is σ = 2711520. Its totient is φ = 1323152.

The previous prime is 2009173. The next prime is 2009191. The reversal of 2009181 is 1819002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2009181 - 2³ = 2009173 is a prime.

It is a super-2 number, since 2×2009181² = 8073616581522, which contains 22 as substring.

It is a Curzon number.

2009181 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2009171) 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, 3786 + ... + 4283.

It is an arithmetic number, because the mean of its divisors is an integer number (338940).

2^2009181 is an apocalyptic number.

It is an amenable number.

2009181 is a deficient number, since it is larger than the sum of its proper divisors (702339).

2009181 is an equidigital number, since it uses as much as digits as its factorization.

2009181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8155.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 2009181 is about 1417.4558194173. The cubic root of 2009181 is about 126.1845996597.

The spelling of 2009181 in words is "two million, nine thousand, one hundred eighty-one".