11581911 has 12 divisors (see below), whose sum is σ = 18250440. Its totient is φ = 7019280.

The previous prime is 11581907. The next prime is 11581937. The reversal of 11581911 is 11918511.

It is not a de Polignac number, because 11581911 - 2² = 11581907 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11581901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58396 + ... + 58593.

It is an arithmetic number, because the mean of its divisors is an integer number (1520870).

Almost surely, 2^11581911 is an apocalyptic number.

11581911 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11581911 is a deficient number, since it is larger than the sum of its proper divisors (6668529).

11581911 is a wasteful number, since it uses less digits than its factorization.

11581911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117006 (or 117003 counting only the distinct ones).

The product of its digits is 360, while the sum is 27.

The square root of 11581911 is about 3403.2206804731. The cubic root of 11581911 is about 226.2525109862.

The spelling of 11581911 in words is "eleven million, five hundred eighty-one thousand, nine hundred eleven".