1821218113 has 16 divisors (see below), whose sum is σ = 2143274112. Its totient is φ = 1525680000.

The previous prime is 1821218111. The next prime is 1821218117. The reversal of 1821218113 is 3118121281.

It is not a de Polignac number, because 1821218113 - 2¹ = 1821218111 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1821218111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75348 + ... + 96538.

It is an arithmetic number, because the mean of its divisors is an integer number (133954632).

Almost surely, 2^1821218113 is an apocalyptic number.

1821218113 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1821218113 is a deficient number, since it is larger than the sum of its proper divisors (322055999).

1821218113 is a wasteful number, since it uses less digits than its factorization.

1821218113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21816.

The product of its digits is 768, while the sum is 28.

The square root of 1821218113 is about 42675.7321319740. The cubic root of 1821218113 is about 1221.2014753870.

Adding to 1821218113 its reverse (3118121281), we get a palindrome (4939339394).

The spelling of 1821218113 in words is "one billion, eight hundred twenty-one million, two hundred eighteen thousand, one hundred thirteen".