11591661 has 4 divisors (see below), whose sum is σ = 15455552. Its totient is φ = 7727772.

The previous prime is 11591659. The next prime is 11591681. The reversal of 11591661 is 16619511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 11591661 - 2¹ = 11591659 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11591611) 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, 1931941 + ... + 1931946.

It is an arithmetic number, because the mean of its divisors is an integer number (3863888).

Almost surely, 2^11591661 is an apocalyptic number.

It is an amenable number.

11591661 is a deficient number, since it is larger than the sum of its proper divisors (3863891).

11591661 is an equidigital number, since it uses as much as digits as its factorization.

11591661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3863890.

The product of its digits is 1620, while the sum is 30.

The square root of 11591661 is about 3404.6528457392. The cubic root of 11591661 is about 226.3159818952.

The spelling of 11591661 in words is "eleven million, five hundred ninety-one thousand, six hundred sixty-one".