20729017 has 2 divisors, whose sum is σ = 20729018. Its totient is φ = 20729016.

The previous prime is 20729011. The next prime is 20729041. The reversal of 20729017 is 71092702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12138256 + 8590761 = 3484^2 + 2931^2 .

It is a cyclic number.

It is not a de Polignac number, because 20729017 - 2¹⁹ = 20204729 is a prime.

It is not a weakly prime, because it can be changed into another prime (20729011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10364508 + 10364509.

It is an arithmetic number, because the mean of its divisors is an integer number (10364509).

Almost surely, 2^20729017 is an apocalyptic number.

It is an amenable number.

20729017 is a deficient number, since it is larger than the sum of its proper divisors (1).

20729017 is an equidigital number, since it uses as much as digits as its factorization.

20729017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 20729017 is about 4552.9130235488. The cubic root of 20729017 is about 274.7005754774.

The spelling of 20729017 in words is "twenty million, seven hundred twenty-nine thousand, seventeen".