10991509 has 2 divisors, whose sum is σ = 10991510. Its totient is φ = 10991508.

The previous prime is 10991501. The next prime is 10991569. The reversal of 10991509 is 90519901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10176100 + 815409 = 3190^2 + 903^2 .

It is a cyclic number.

It is not a de Polignac number, because 10991509 - 2³ = 10991501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10991501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5495754 + 5495755.

It is an arithmetic number, because the mean of its divisors is an integer number (5495755).

Almost surely, 2^10991509 is an apocalyptic number.

It is an amenable number.

10991509 is a deficient number, since it is larger than the sum of its proper divisors (1).

10991509 is an equidigital number, since it uses as much as digits as its factorization.

10991509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3645, while the sum is 34.

The square root of 10991509 is about 3315.3444768229. The cubic root of 10991509 is about 222.3407706451.

The spelling of 10991509 in words is "ten million, nine hundred ninety-one thousand, five hundred nine".