18661133 has 2 divisors, whose sum is σ = 18661134. Its totient is φ = 18661132.

The previous prime is 18661129. The next prime is 18661157. The reversal of 18661133 is 33116681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17952169 + 708964 = 4237^2 + 842^2 .

It is a cyclic number.

It is not a de Polignac number, because 18661133 - 2² = 18661129 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18661096 and 18661105.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18661193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9330566 + 9330567.

It is an arithmetic number, because the mean of its divisors is an integer number (9330567).

Almost surely, 2^18661133 is an apocalyptic number.

It is an amenable number.

18661133 is a deficient number, since it is larger than the sum of its proper divisors (1).

18661133 is an equidigital number, since it uses as much as digits as its factorization.

18661133 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 29.

The square root of 18661133 is about 4319.8533539925. The cubic root of 18661133 is about 265.2442651069.

The spelling of 18661133 in words is "eighteen million, six hundred sixty-one thousand, one hundred thirty-three".