1820111011 has 4 divisors (see below), whose sum is σ = 1829541832. Its totient is φ = 1810680192.

The previous prime is 1820110979. The next prime is 1820111047. The reversal of 1820111011 is 1101110281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1101110281 = 17 ⋅64771193.

It is a cyclic number.

It is not a de Polignac number, because 1820111011 - 2⁵ = 1820110979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1820111081) 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, 4715121 + ... + 4715506.

It is an arithmetic number, because the mean of its divisors is an integer number (457385458).

Almost surely, 2^1820111011 is an apocalyptic number.

1820111011 is a deficient number, since it is larger than the sum of its proper divisors (9430821).

1820111011 is an equidigital number, since it uses as much as digits as its factorization.

1820111011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9430820.

The product of its (nonzero) digits is 16, while the sum is 16.

The square root of 1820111011 is about 42662.7590645518. The cubic root of 1820111011 is about 1220.9539727890.

Adding to 1820111011 its reverse (1101110281), we get a palindrome (2921221292).

The spelling of 1820111011 in words is "one billion, eight hundred twenty million, one hundred eleven thousand, eleven".