1191731 has 2 divisors, whose sum is σ = 1191732. Its totient is φ = 1191730.

The previous prime is 1191727. The next prime is 1191739. The reversal of 1191731 is 1371911.

It is a weak prime.

It is an emirp because it is prime and its reverse (1371911) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1191731 - 2² = 1191727 is a prime.

It is a super-2 number, since 2×1191731² = 2840445552722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1191697 and 1191706.

It is not a weakly prime, because it can be changed into another prime (1191739) 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 as a sum of consecutive naturals, namely, 595865 + 595866.

It is an arithmetic number, because the mean of its divisors is an integer number (595866).

2^1191731 is an apocalyptic number.

1191731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191731 is an equidigital number, since it uses as much as digits as its factorization.

1191731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 189, while the sum is 23.

The square root of 1191731 is about 1091.6643256972. The cubic root of 1191731 is about 106.0212073386.

The spelling of 1191731 in words is "one million, one hundred ninety-one thousand, seven hundred thirty-one".