181820069 has 2 divisors, whose sum is σ = 181820070. Its totient is φ = 181820068.

The previous prime is 181820033. The next prime is 181820153. The reversal of 181820069 is 960028181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99700225 + 82119844 = 9985^2 + 9062^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181820069 is a prime.

It is a super-2 number, since 2×181820069² = 66117074982329522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181820269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90910034 + 90910035.

It is an arithmetic number, because the mean of its divisors is an integer number (90910035).

Almost surely, 2^181820069 is an apocalyptic number.

It is an amenable number.

181820069 is a deficient number, since it is larger than the sum of its proper divisors (1).

181820069 is an equidigital number, since it uses as much as digits as its factorization.

181820069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 181820069 is about 13484.0672276580. The cubic root of 181820069 is about 566.5182949880.

The spelling of 181820069 in words is "one hundred eighty-one million, eight hundred twenty thousand, sixty-nine".