20178089 has 2 divisors, whose sum is σ = 20178090. Its totient is φ = 20178088.

The previous prime is 20178079. The next prime is 20178097. The reversal of 20178089 is 98087102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20178064 + 25 = 4492^2 + 5^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20178089 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20178049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10089044 + 10089045.

It is an arithmetic number, because the mean of its divisors is an integer number (10089045).

Almost surely, 2^20178089 is an apocalyptic number.

It is an amenable number.

20178089 is a deficient number, since it is larger than the sum of its proper divisors (1).

20178089 is an equidigital number, since it uses as much as digits as its factorization.

20178089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 20178089 is about 4492.0027827240. The cubic root of 20178089 is about 272.2450619058.

The spelling of 20178089 in words is "twenty million, one hundred seventy-eight thousand, eighty-nine".