1091287 has 2 divisors, whose sum is σ = 1091288. Its totient is φ = 1091286.

The previous prime is 1091273. The next prime is 1091329. The reversal of 1091287 is 7821901.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1091287 - 2⁷ = 1091159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1091257) 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, 545643 + 545644.

It is an arithmetic number, because the mean of its divisors is an integer number (545644).

2^1091287 is an apocalyptic number.

1091287 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091287 is an equidigital number, since it uses as much as digits as its factorization.

1091287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 1091287 is about 1044.6468302733. The cubic root of 1091287 is about 102.9547355073.

It can be divided in two parts, 1091 and 287, that added together give a triangular number (1378 = T₅₂).

The spelling of 1091287 in words is "one million, ninety-one thousand, two hundred eighty-seven".