11965591 has 4 divisors (see below), whose sum is σ = 13053384. Its totient is φ = 10877800.

The previous prime is 11965579. The next prime is 11965607. The reversal of 11965591 is 19556911.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11965591 - 2¹⁷ = 11834519 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11965591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11965531) 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 3 ways as a sum of consecutive naturals, for example, 543880 + ... + 543901.

It is an arithmetic number, because the mean of its divisors is an integer number (3263346).

Almost surely, 2^11965591 is an apocalyptic number.

11965591 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11965591 is a deficient number, since it is larger than the sum of its proper divisors (1087793).

11965591 is a wasteful number, since it uses less digits than its factorization.

11965591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1087792.

The product of its digits is 12150, while the sum is 37.

The square root of 11965591 is about 3459.1315384067. The cubic root of 11965591 is about 228.7238141763.

The spelling of 11965591 in words is "eleven million, nine hundred sixty-five thousand, five hundred ninety-one".