1191971 has 6 divisors (see below), whose sum is σ = 1310316. Its totient is φ = 1083500.

The previous prime is 1191947. The next prime is 1191973. The reversal of 1191971 is 1791911.

It is not a de Polignac number, because 1191971 - 2¹⁰ = 1190947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1191973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4805 + ... + 5046.

It is an arithmetic number, because the mean of its divisors is an integer number (218386).

2^1191971 is an apocalyptic number.

1191971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1191971 is a deficient number, since it is larger than the sum of its proper divisors (118345).

1191971 is an equidigital number, since it uses as much as digits as its factorization.

1191971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9873 (or 9862 counting only the distinct ones).

The product of its digits is 567, while the sum is 29.

The square root of 1191971 is about 1091.7742440633. The cubic root of 1191971 is about 106.0283239843.

The spelling of 1191971 in words is "one million, one hundred ninety-one thousand, nine hundred seventy-one".