11999591 has 4 divisors (see below), whose sum is σ = 12413400. Its totient is φ = 11585784.

The previous prime is 11999563. The next prime is 11999653. The reversal of 11999591 is 19599911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19599911 = 29 ⋅675859.

It is a cyclic number.

It is not a de Polignac number, because 11999591 - 2⁶ = 11999527 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 (11999531) 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, 206861 + ... + 206918.

It is an arithmetic number, because the mean of its divisors is an integer number (3103350).

Almost surely, 2^11999591 is an apocalyptic number.

11999591 is a deficient number, since it is larger than the sum of its proper divisors (413809).

11999591 is an equidigital number, since it uses as much as digits as its factorization.

11999591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413808.

The product of its digits is 32805, while the sum is 44.

The square root of 11999591 is about 3464.0425805697. The cubic root of 11999591 is about 228.9402474360.

The spelling of 11999591 in words is "eleven million, nine hundred ninety-nine thousand, five hundred ninety-one".