1818190909 has 4 divisors (see below), whose sum is σ = 1818400000. Its totient is φ = 1817981820.

The previous prime is 1818190901. The next prime is 1818190939. The reversal of 1818190909 is 9090918181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1818190909 - 2³ = 1818190901 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818190901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90909 + ... + 109090.

It is an arithmetic number, because the mean of its divisors is an integer number (454600000).

Almost surely, 2^1818190909 is an apocalyptic number.

It is an amenable number.

1818190909 is a deficient number, since it is larger than the sum of its proper divisors (209091).

1818190909 is an equidigital number, since it uses as much as digits as its factorization.

1818190909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209090.

The product of its (nonzero) digits is 46656, while the sum is 46.

The square root of 1818190909 is about 42640.2498702810. The cubic root of 1818190909 is about 1220.5244786506.

The spelling of 1818190909 in words is "one billion, eight hundred eighteen million, one hundred ninety thousand, nine hundred nine".