11555891 has 8 divisors (see below), whose sum is σ = 12247200. Its totient is φ = 10884160.

The previous prime is 11555783. The next prime is 11555909. The reversal of 11555891 is 19855511.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11555891 - 2¹⁸ = 11293747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11554891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3671 + ... + 6048.

It is an arithmetic number, because the mean of its divisors is an integer number (1530900).

Almost surely, 2^11555891 is an apocalyptic number.

11555891 is a deficient number, since it is larger than the sum of its proper divisors (691309).

11555891 is an equidigital number, since it uses as much as digits as its factorization.

11555891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9789.

The product of its digits is 9000, while the sum is 35.

The square root of 11555891 is about 3399.3956815881. The cubic root of 11555891 is about 226.0829504677.

The spelling of 11555891 in words is "eleven million, five hundred fifty-five thousand, eight hundred ninety-one".