1810181 has 8 divisors (see below), whose sum is σ = 1858584. Its totient is φ = 1762560.

The previous prime is 1810153. The next prime is 1810199.

1810181 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 30625 + 1779556 = 175^2 + 1334^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1810181 is a prime.

It is a super-2 number, since 2×1810181² = 6553510505522, which contains 22 as substring.

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

1810181 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1810481) 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, 9911 + ... + 10091.

It is an arithmetic number, because the mean of its divisors is an integer number (232323).

2^1810181 is an apocalyptic number.

It is an amenable number.

1810181 is a deficient number, since it is larger than the sum of its proper divisors (48403).

1810181 is a wasteful number, since it uses less digits than its factorization.

1810181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391.

The product of its (nonzero) digits is 64, while the sum is 20.

The square root of 1810181 is about 1345.4296711460. The cubic root of 1810181 is about 121.8729529352.

It can be divided in two parts, 1810 and 181, that added together give a palindrome (1991).

The spelling of 1810181 in words is "one million, eight hundred ten thousand, one hundred eighty-one".