11663591 has 4 divisors (see below), whose sum is σ = 11681352. Its totient is φ = 11645832.

The previous prime is 11663579. The next prime is 11663593. The reversal of 11663591 is 19536611.

It is a happy number.

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 11663591 - 2⁶ = 11663527 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 (11663593) 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, 7856 + ... + 9221.

It is an arithmetic number, because the mean of its divisors is an integer number (2920338).

Almost surely, 2^11663591 is an apocalyptic number.

11663591 is a deficient number, since it is larger than the sum of its proper divisors (17761).

11663591 is an equidigital number, since it uses as much as digits as its factorization.

11663591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17760.

The product of its digits is 4860, while the sum is 32.

The square root of 11663591 is about 3415.1999941438. The cubic root of 11663591 is about 226.7831381903.

The spelling of 11663591 in words is "eleven million, six hundred sixty-three thousand, five hundred ninety-one".