11906581 has 4 divisors (see below), whose sum is σ = 11939392. Its totient is φ = 11873772.

The previous prime is 11906569. The next prime is 11906591. The reversal of 11906581 is 18560911.

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 a cyclic number.

It is not a de Polignac number, because 11906581 - 2¹¹ = 11904533 is a prime.

It is a super-2 number, since 2×11906581² = 283533342219122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11906551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15855 + ... + 16588.

It is an arithmetic number, because the mean of its divisors is an integer number (2984848).

Almost surely, 2^11906581 is an apocalyptic number.

It is an amenable number.

11906581 is a deficient number, since it is larger than the sum of its proper divisors (32811).

11906581 is an equidigital number, since it uses as much as digits as its factorization.

11906581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32810.

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 11906581 is about 3450.5913985866. The cubic root of 11906581 is about 228.3471998020.

The spelling of 11906581 in words is "eleven million, nine hundred six thousand, five hundred eighty-one".