11973509 has 2 divisors, whose sum is σ = 11973510. Its totient is φ = 11973508.

The previous prime is 11973499. The next prime is 11973529. The reversal of 11973509 is 90537911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8352100 + 3621409 = 2890^2 + 1903^2 .

It is a cyclic number.

It is not a de Polignac number, because 11973509 - 2¹² = 11969413 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11973529) 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 as a sum of consecutive naturals, namely, 5986754 + 5986755.

It is an arithmetic number, because the mean of its divisors is an integer number (5986755).

Almost surely, 2^11973509 is an apocalyptic number.

It is an amenable number.

11973509 is a deficient number, since it is larger than the sum of its proper divisors (1).

11973509 is an equidigital number, since it uses as much as digits as its factorization.

11973509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8505, while the sum is 35.

The square root of 11973509 is about 3460.2758560554. The cubic root of 11973509 is about 228.7742542489.

The spelling of 11973509 in words is "eleven million, nine hundred seventy-three thousand, five hundred nine".