20159917 has 2 divisors, whose sum is σ = 20159918. Its totient is φ = 20159916.

The previous prime is 20159911. The next prime is 20159929. The reversal of 20159917 is 71995102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20124196 + 35721 = 4486^2 + 189^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20159917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20159911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10079958 + 10079959.

It is an arithmetic number, because the mean of its divisors is an integer number (10079959).

Almost surely, 2^20159917 is an apocalyptic number.

It is an amenable number.

20159917 is a deficient number, since it is larger than the sum of its proper divisors (1).

20159917 is an equidigital number, since it uses as much as digits as its factorization.

20159917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 20159917 is about 4489.9796213346. The cubic root of 20159917 is about 272.1633111326.

The spelling of 20159917 in words is "twenty million, one hundred fifty-nine thousand, nine hundred seventeen".