1231191 has 24 divisors (see below), whose sum is σ = 2031120. Its totient is φ = 711936.

The previous prime is 1231177. The next prime is 1231193. The reversal of 1231191 is 1911321.

It is not a de Polignac number, because 1231191 - 2⁶ = 1231127 is a prime.

1231191 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231193) 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 23 ways as a sum of consecutive naturals, for example, 1680 + ... + 2298.

It is an arithmetic number, because the mean of its divisors is an integer number (84630).

2^1231191 is an apocalyptic number.

1231191 is a deficient number, since it is larger than the sum of its proper divisors (799929).

1231191 is a wasteful number, since it uses less digits than its factorization.

1231191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655 (or 652 counting only the distinct ones).

The product of its digits is 54, while the sum is 18.

The square root of 1231191 is about 1109.5904649915. The cubic root of 1231191 is about 107.1786981045.

The spelling of 1231191 in words is "one million, two hundred thirty-one thousand, one hundred ninety-one".