11666221 has 8 divisors (see below), whose sum is σ = 13912704. Its totient is φ = 9564720.

The previous prime is 11666191. The next prime is 11666227. The reversal of 11666221 is 12266611.

11666221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 11666221 - 2²³ = 3277613 is a prime.

It is a super-2 number, since 2×11666221² = 272201424841682, 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 (11666227) 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, 36070 + ... + 36391.

It is an arithmetic number, because the mean of its divisors is an integer number (1739088).

Almost surely, 2^11666221 is an apocalyptic number.

It is an amenable number.

11666221 is a deficient number, since it is larger than the sum of its proper divisors (2246483).

11666221 is an equidigital number, since it uses as much as digits as its factorization.

11666221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72491.

The product of its digits is 864, while the sum is 25.

The square root of 11666221 is about 3415.5850157769. The cubic root of 11666221 is about 226.8001825359.

The spelling of 11666221 in words is "eleven million, six hundred sixty-six thousand, two hundred twenty-one".