11861509 has 12 divisors (see below), whose sum is σ = 13138272. Its totient is φ = 10700360.

The previous prime is 11861467. The next prime is 11861527. The reversal of 11861509 is 90516811.

It is not a de Polignac number, because 11861509 - 2¹¹ = 11859461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11861539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19914 + ... + 20500.

It is an arithmetic number, because the mean of its divisors is an integer number (1094856).

Almost surely, 2^11861509 is an apocalyptic number.

It is an amenable number.

11861509 is a deficient number, since it is larger than the sum of its proper divisors (1276763).

11861509 is a wasteful number, since it uses less digits than its factorization.

11861509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 776 (or 765 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 11861509 is about 3444.0541517229. The cubic root of 11861509 is about 228.0587016698.

The spelling of 11861509 in words is "eleven million, eight hundred sixty-one thousand, five hundred nine".