11666021 has 2 divisors, whose sum is σ = 11666022. Its totient is φ = 11666020.

The previous prime is 11665963. The next prime is 11666027. The reversal of 11666021 is 12066611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9150625 + 2515396 = 3025^2 + 1586^2 .

It is an emirp because it is prime and its reverse (12066611) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11666021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11666027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5833010 + 5833011.

It is an arithmetic number, because the mean of its divisors is an integer number (5833011).

Almost surely, 2^11666021 is an apocalyptic number.

It is an amenable number.

11666021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11666021 is an equidigital number, since it uses as much as digits as its factorization.

11666021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 11666021 is about 3415.5557380901. Note that the first 3 decimals coincide. The cubic root of 11666021 is about 226.7988864779.

The spelling of 11666021 in words is "eleven million, six hundred sixty-six thousand, twenty-one".