20705017 has 2 divisors, whose sum is σ = 20705018. Its totient is φ = 20705016.

The previous prime is 20704987. The next prime is 20705021. The reversal of 20705017 is 71050702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13366336 + 7338681 = 3656^2 + 2709^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20705017 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20705917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10352508 + 10352509.

It is an arithmetic number, because the mean of its divisors is an integer number (10352509).

Almost surely, 2^20705017 is an apocalyptic number.

It is an amenable number.

20705017 is a deficient number, since it is larger than the sum of its proper divisors (1).

20705017 is an equidigital number, since it uses as much as digits as its factorization.

20705017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 490, while the sum is 22.

The square root of 20705017 is about 4550.2765850001. The cubic root of 20705017 is about 274.5945186742.

Adding to 20705017 its reverse (71050702), we get a palindrome (91755719).

The spelling of 20705017 in words is "twenty million, seven hundred five thousand, seventeen".