11957509 has 2 divisors, whose sum is σ = 11957510. Its totient is φ = 11957508.

The previous prime is 11957507. The next prime is 11957513. The reversal of 11957509 is 90575911.

It is a happy number.

11957509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9641025 + 2316484 = 3105^2 + 1522^2 .

It is a cyclic number.

It is not a de Polignac number, because 11957509 - 2¹ = 11957507 is a prime.

Together with 11957507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11957501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5978754 + 5978755.

It is an arithmetic number, because the mean of its divisors is an integer number (5978755).

Almost surely, 2^11957509 is an apocalyptic number.

It is an amenable number.

11957509 is a deficient number, since it is larger than the sum of its proper divisors (1).

11957509 is an equidigital number, since it uses as much as digits as its factorization.

11957509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14175, while the sum is 37.

The square root of 11957509 is about 3457.9631287797. The cubic root of 11957509 is about 228.6723064206.

The spelling of 11957509 in words is "eleven million, nine hundred fifty-seven thousand, five hundred nine".