18066817 has 2 divisors, whose sum is σ = 18066818. Its totient is φ = 18066816.

The previous prime is 18066809. The next prime is 18066821. The reversal of 18066817 is 71866081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12383361 + 5683456 = 3519^2 + 2384^2 .

It is a cyclic number.

It is not a de Polignac number, because 18066817 - 2³ = 18066809 is a prime.

It is a super-2 number, since 2×18066817² = 652819753022978, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18066827) 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 as a sum of consecutive naturals, namely, 9033408 + 9033409.

It is an arithmetic number, because the mean of its divisors is an integer number (9033409).

Almost surely, 2^18066817 is an apocalyptic number.

It is an amenable number.

18066817 is a deficient number, since it is larger than the sum of its proper divisors (1).

18066817 is an equidigital number, since it uses as much as digits as its factorization.

18066817 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 18066817 is about 4250.5078520102. The cubic root of 18066817 is about 262.3980169222.

It can be divided in two parts, 180 and 66817, that multiplied together give a triangular number (12027060 = T₄₉₀₄).

The spelling of 18066817 in words is "eighteen million, sixty-six thousand, eight hundred seventeen".