1131509 has 2 divisors, whose sum is σ = 1131510. Its totient is φ = 1131508.

The previous prime is 1131491. The next prime is 1131523. The reversal of 1131509 is 9051311.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1044484 + 87025 = 1022^2 + 295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131509 - 2⁸ = 1131253 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1131569) 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, 565754 + 565755.

It is an arithmetic number, because the mean of its divisors is an integer number (565755).

2^1131509 is an apocalyptic number.

It is an amenable number.

1131509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1131509 is an equidigital number, since it uses as much as digits as its factorization.

1131509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 135, while the sum is 20.

The square root of 1131509 is about 1063.7241183690. The cubic root of 1131509 is about 104.2043872635.

The spelling of 1131509 in words is "one million, one hundred thirty-one thousand, five hundred nine".