1811231 has 4 divisors (see below), whose sum is σ = 1917792. Its totient is φ = 1704672.

The previous prime is 1811219. The next prime is 1811287. The reversal of 1811231 is 1321181.

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

It is a cyclic number.

It is not a de Polignac number, because 1811231 - 2⁶ = 1811167 is a prime.

It is a super-2 number, since 2×1811231² = 6561115470722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 106543 = 1811231 / (1 + 8 + 1 + 1 + 2 + 3 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1811291) 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, 53255 + ... + 53288.

It is an arithmetic number, because the mean of its divisors is an integer number (479448).

2^1811231 is an apocalyptic number.

1811231 is a deficient number, since it is larger than the sum of its proper divisors (106561).

1811231 is a wasteful number, since it uses less digits than its factorization.

1811231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106560.

The product of its digits is 48, while the sum is 17.

The square root of 1811231 is about 1345.8198244936. The cubic root of 1811231 is about 121.8965126171.

The spelling of 1811231 in words is "one million, eight hundred eleven thousand, two hundred thirty-one".