1818181 has 8 divisors (see below), whose sum is σ = 1900800. Its totient is φ = 1737120.

The previous prime is 1818163. The next prime is 1818199.

1818181 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (1818163) and next prime (1818199).

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-1818181 is a prime.

It is a super-2 number, since 2×1818181² = 6611564297522, which contains 22 as substring.

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

1818181 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

1818181 is an undulating number in base 10.

1818181 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818151) 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 7 ways as a sum of consecutive naturals, for example, 2430 + ... + 3088.

It is an arithmetic number, because the mean of its divisors is an integer number (237600).

2^1818181 is an apocalyptic number.

It is an amenable number.

1818181 is a deficient number, since it is larger than the sum of its proper divisors (82619).

1818181 is an equidigital number, since it uses as much as digits as its factorization.

1818181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779.

The product of its digits is 512, while the sum is 28.

The square root of 1818181 is about 1348.3994215365. The cubic root of 1818181 is about 122.0522261392.

The spelling of 1818181 in words is "one million, eight hundred eighteen thousand, one hundred eighty-one".