11959509 has 4 divisors (see below), whose sum is σ = 15946016. Its totient is φ = 7973004.

The previous prime is 11959489. The next prime is 11959543. The reversal of 11959509 is 90595911.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 11959509 - 2⁸ = 11959253 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 (11959559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1993249 + ... + 1993254.

It is an arithmetic number, because the mean of its divisors is an integer number (3986504).

Almost surely, 2^11959509 is an apocalyptic number.

It is an amenable number.

11959509 is a deficient number, since it is larger than the sum of its proper divisors (3986507).

11959509 is an equidigital number, since it uses as much as digits as its factorization.

11959509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3986506.

The product of its (nonzero) digits is 18225, while the sum is 39.

The square root of 11959509 is about 3458.2523042716. The cubic root of 11959509 is about 228.6850548706.

The spelling of 11959509 in words is "eleven million, nine hundred fifty-nine thousand, five hundred nine".