20008108909 has 2 divisors, whose sum is σ = 20008108910. Its totient is φ = 20008108908.

The previous prime is 20008108907. The next prime is 20008108931. The reversal of 20008108909 is 90980180002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17324350884 + 2683758025 = 131622^2 + 51805^2 .

It is a cyclic number.

It is not a de Polignac number, because 20008108909 - 2¹ = 20008108907 is a prime.

It is a super-2 number, since 2×20008108909² (a number of 21 digits) contains 22 as substring.

Together with 20008108907, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20008108907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10004054454 + 10004054455.

It is an arithmetic number, because the mean of its divisors is an integer number (10004054455).

Almost surely, 2^20008108909 is an apocalyptic number.

It is an amenable number.

20008108909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20008108909 is an equidigital number, since it uses as much as digits as its factorization.

20008108909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 37.

The spelling of 20008108909 in words is "twenty billion, eight million, one hundred eight thousand, nine hundred nine".