11666381 has 8 divisors (see below), whose sum is σ = 12118680. Its totient is φ = 11217472.

The previous prime is 11666371. The next prime is 11666383. The reversal of 11666381 is 18366611.

It can be written as a sum of positive squares in 4 ways, for example, as 8462281 + 3204100 = 2909^2 + 1790^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11666381 is a prime.

It is a super-2 number, since 2×11666381² = 272208891274322, which contains 22 as substring.

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 (11666383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7811 + ... + 9183.

It is an arithmetic number, because the mean of its divisors is an integer number (1514835).

Almost surely, 2^11666381 is an apocalyptic number.

It is an amenable number.

11666381 is a deficient number, since it is larger than the sum of its proper divisors (452299).

11666381 is a wasteful number, since it uses less digits than its factorization.

11666381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1695.

The product of its digits is 5184, while the sum is 32.

The square root of 11666381 is about 3415.6084377458. The cubic root of 11666381 is about 226.8012193716.

The spelling of 11666381 in words is "eleven million, six hundred sixty-six thousand, three hundred eighty-one".