1811321312 has 48 divisors (see below), whose sum is σ = 3638017152. Its totient is φ = 887493120.

The previous prime is 1811321261. The next prime is 1811321327. The reversal of 1811321312 is 2131231181.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 570353 + ... + 573519.

It is an arithmetic number, because the mean of its divisors is an integer number (75792024).

Almost surely, 2^1811321312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1811321312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1819008576).

1811321312 is an abundant number, since it is smaller than the sum of its proper divisors (1826695840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1811321312 is a wasteful number, since it uses less digits than its factorization.

1811321312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3531 (or 3523 counting only the distinct ones).

The product of its digits is 288, while the sum is 23.

The square root of 1811321312 is about 42559.6206750013. The cubic root of 1811321312 is about 1218.9853859374.

Adding to 1811321312 its reverse (2131231181), we get a palindrome (3942552493).

The spelling of 1811321312 in words is "one billion, eight hundred eleven million, three hundred twenty-one thousand, three hundred twelve".