11943581 has 4 divisors (see below), whose sum is σ = 12862332. Its totient is φ = 11024832.

The previous prime is 11943577. The next prime is 11943599. The reversal of 11943581 is 18534911.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5359225 + 6584356 = 2315^2 + 2566^2 .

It is not a de Polignac number, because 11943581 - 2² = 11943577 is a prime.

It is a super-2 number, since 2×11943581² = 285298254207122, 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 (11943511) 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, 459356 + ... + 459381.

It is an arithmetic number, because the mean of its divisors is an integer number (3215583).

Almost surely, 2^11943581 is an apocalyptic number.

It is an amenable number.

11943581 is a deficient number, since it is larger than the sum of its proper divisors (918751).

11943581 is an equidigital number, since it uses as much as digits as its factorization.

11943581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918750.

The product of its digits is 4320, while the sum is 32.

The square root of 11943581 is about 3455.9486396647. The cubic root of 11943581 is about 228.5834867709.

The spelling of 11943581 in words is "eleven million, nine hundred forty-three thousand, five hundred eighty-one".