1813811 has 4 divisors (see below), whose sum is σ = 1827000. Its totient is φ = 1800624.

The previous prime is 1813793. The next prime is 1813813. The reversal of 1813811 is 1183181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1813811 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 (1813813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6386 + ... + 6663.

It is an arithmetic number, because the mean of its divisors is an integer number (456750).

2^1813811 is an apocalyptic number.

1813811 is a deficient number, since it is larger than the sum of its proper divisors (13189).

1813811 is a wasteful number, since it uses less digits than its factorization.

1813811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13188.

The product of its digits is 192, while the sum is 23.

The square root of 1813811 is about 1346.7780069484. The cubic root of 1813811 is about 121.9543634737.

Adding to 1813811 its reverse (1183181), we get a palindrome (2996992).

The spelling of 1813811 in words is "one million, eight hundred thirteen thousand, eight hundred eleven".