1812181 has 16 divisors (see below), whose sum is σ = 2188800. Its totient is φ = 1467648.

The previous prime is 1812157. The next prime is 1812199.

1812181 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1812181 - 2⁷ = 1812053 is a prime.

It is a super-2 number, since 2×1812181² = 6567999953522, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

1812181 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1812121) 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 15 ways as a sum of consecutive naturals, for example, 15981 + ... + 16093.

It is an arithmetic number, because the mean of its divisors is an integer number (136800).

2^1812181 is an apocalyptic number.

It is an amenable number.

1812181 is a deficient number, since it is larger than the sum of its proper divisors (376619).

1812181 is a wasteful number, since it uses less digits than its factorization.

1812181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228.

The product of its digits is 128, while the sum is 22.

The square root of 1812181 is about 1346.1727229446. The cubic root of 1812181 is about 121.9178206753.

The spelling of 1812181 in words is "one million, eight hundred twelve thousand, one hundred eighty-one".