11991583 has 2 divisors, whose sum is σ = 11991584. Its totient is φ = 11991582.

The previous prime is 11991523. The next prime is 11991601. The reversal of 11991583 is 38519911.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (38519911) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11991583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11991523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5995791 + 5995792.

It is an arithmetic number, because the mean of its divisors is an integer number (5995792).

Almost surely, 2^11991583 is an apocalyptic number.

11991583 is a deficient number, since it is larger than the sum of its proper divisors (1).

11991583 is an equidigital number, since it uses as much as digits as its factorization.

11991583 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 37.

The square root of 11991583 is about 3462.8865127232. The cubic root of 11991583 is about 228.8893078807.

The spelling of 11991583 in words is "eleven million, nine hundred ninety-one thousand, five hundred eighty-three".