11666521 has 2 divisors, whose sum is σ = 11666522. Its totient is φ = 11666520.

The previous prime is 11666491. The next prime is 11666533. The reversal of 11666521 is 12566611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9217296 + 2449225 = 3036^2 + 1565^2 .

It is a cyclic number.

It is not a de Polignac number, because 11666521 - 2⁷ = 11666393 is a prime.

It is a super-2 number, since 2×11666521² = 272215424486882, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11666521.

It is not a weakly prime, because it can be changed into another prime (11666021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5833260 + 5833261.

It is an arithmetic number, because the mean of its divisors is an integer number (5833261).

Almost surely, 2^11666521 is an apocalyptic number.

It is an amenable number.

11666521 is a deficient number, since it is larger than the sum of its proper divisors (1).

11666521 is an equidigital number, since it uses as much as digits as its factorization.

11666521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 28.

The square root of 11666521 is about 3415.6289318367. The cubic root of 11666521 is about 226.8021265951.

The spelling of 11666521 in words is "eleven million, six hundred sixty-six thousand, five hundred twenty-one".