20642026109 has 2 divisors, whose sum is σ = 20642026110. Its totient is φ = 20642026108.

The previous prime is 20642026063. The next prime is 20642026157. The reversal of 20642026109 is 90162024602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17338305625 + 3303720484 = 131675^2 + 57478^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20642026109 is a prime.

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 (20642026159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10321013054 + 10321013055.

It is an arithmetic number, because the mean of its divisors is an integer number (10321013055).

Almost surely, 2^20642026109 is an apocalyptic number.

It is an amenable number.

20642026109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20642026109 is an equidigital number, since it uses as much as digits as its factorization.

20642026109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 32.

The spelling of 20642026109 in words is "twenty billion, six hundred forty-two million, twenty-six thousand, one hundred nine".