1091247109 has 2 divisors, whose sum is σ = 1091247110. Its totient is φ = 1091247108.

The previous prime is 1091247071. The next prime is 1091247133. The reversal of 1091247109 is 9017421901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 548590084 + 542657025 = 23422^2 + 23295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1091247109 - 2²³ = 1082858501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1091247139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545623554 + 545623555.

It is an arithmetic number, because the mean of its divisors is an integer number (545623555).

Almost surely, 2^1091247109 is an apocalyptic number.

It is an amenable number.

1091247109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091247109 is an equidigital number, since it uses as much as digits as its factorization.

1091247109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 1091247109 is about 33034.0295604396. The cubic root of 1091247109 is about 1029.5348101988.

The spelling of 1091247109 in words is "one billion, ninety-one million, two hundred forty-seven thousand, one hundred nine".