11666661 has 4 divisors (see below), whose sum is σ = 15555552. Its totient is φ = 7777772.

The previous prime is 11666653. The next prime is 11666663. The reversal of 11666661 is 16666611.

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 11666661 - 2³ = 11666653 is a prime.

It is a super-2 number, since 2×11666661² = 272221957777842, which contains 22 as substring.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11666663) 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, 1944441 + ... + 1944446.

It is an arithmetic number, because the mean of its divisors is an integer number (3888888).

Almost surely, 2^11666661 is an apocalyptic number.

It is an amenable number.

11666661 is a deficient number, since it is larger than the sum of its proper divisors (3888891).

11666661 is an equidigital number, since it uses as much as digits as its factorization.

11666661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3888890.

The product of its digits is 7776, while the sum is 33.

The square root of 11666661 is about 3415.6494258047. The cubic root of 11666661 is about 226.8030338113.

The spelling of 11666661 in words is "eleven million, six hundred sixty-six thousand, six hundred sixty-one".