20678234209 has 2 divisors, whose sum is σ = 20678234210. Its totient is φ = 20678234208.

The previous prime is 20678234207. The next prime is 20678234221. The reversal of 20678234209 is 90243287602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13572250000 + 7105984209 = 116500^2 + 84297^2 .

It is a cyclic number.

It is not a de Polignac number, because 20678234209 - 2¹ = 20678234207 is a prime.

Together with 20678234207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20678234207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10339117104 + 10339117105.

It is an arithmetic number, because the mean of its divisors is an integer number (10339117105).

Almost surely, 2^20678234209 is an apocalyptic number.

It is an amenable number.

20678234209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20678234209 is an equidigital number, since it uses as much as digits as its factorization.

20678234209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 43.

The spelling of 20678234209 in words is "twenty billion, six hundred seventy-eight million, two hundred thirty-four thousand, two hundred nine".