20117017909 has 2 divisors, whose sum is σ = 20117017910. Its totient is φ = 20117017908.

The previous prime is 20117017883. The next prime is 20117017913. The reversal of 20117017909 is 90971071102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15085243684 + 5031774225 = 122822^2 + 70935^2 .

It is a cyclic number.

It is not a de Polignac number, because 20117017909 - 2²¹ = 20114920757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20117017009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10058508954 + 10058508955.

It is an arithmetic number, because the mean of its divisors is an integer number (10058508955).

Almost surely, 2^20117017909 is an apocalyptic number.

It is an amenable number.

20117017909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20117017909 is an equidigital number, since it uses as much as digits as its factorization.

20117017909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7938, while the sum is 37.

The spelling of 20117017909 in words is "twenty billion, one hundred seventeen million, seventeen thousand, nine hundred nine".