1811820109 has 8 divisors (see below), whose sum is σ = 2008933920. Its totient is φ = 1620106800.

The previous prime is 1811820091. The next prime is 1811820149. The reversal of 1811820109 is 9010281181.

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 1811820109 - 2⁷ = 1811819981 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 (1811820149) 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, 1349419 + ... + 1350760.

It is an arithmetic number, because the mean of its divisors is an integer number (251116740).

Almost surely, 2^1811820109 is an apocalyptic number.

It is an amenable number.

1811820109 is a deficient number, since it is larger than the sum of its proper divisors (197113811).

1811820109 is a wasteful number, since it uses less digits than its factorization.

1811820109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2700251.

The product of its (nonzero) digits is 1152, while the sum is 31.

The square root of 1811820109 is about 42565.4802510203. The cubic root of 1811820109 is about 1219.0972693539.

The spelling of 1811820109 in words is "one billion, eight hundred eleven million, eight hundred twenty thousand, one hundred nine".