1231811 has 12 divisors (see below), whose sum is σ = 1496592. Its totient is φ = 1009008.

The previous prime is 1231807. The next prime is 1231817. The reversal of 1231811 is 1181321.

It is not a de Polignac number, because 1231811 - 2² = 1231807 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231811.

It is not an unprimeable number, because it can be changed into a prime (1231817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 581 + ... + 1673.

It is an arithmetic number, because the mean of its divisors is an integer number (124716).

2^1231811 is an apocalyptic number.

1231811 is a deficient number, since it is larger than the sum of its proper divisors (264781).

1231811 is a wasteful number, since it uses less digits than its factorization.

1231811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1130 (or 1123 counting only the distinct ones).

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

The square root of 1231811 is about 1109.8698121852. The cubic root of 1231811 is about 107.1966860099.

The spelling of 1231811 in words is "one million, two hundred thirty-one thousand, eight hundred eleven".