20728339 has 2 divisors, whose sum is σ = 20728340. Its totient is φ = 20728338.

The previous prime is 20728291. The next prime is 20728387. The reversal of 20728339 is 93382702.

It is a balanced prime because it is at equal distance from previous prime (20728291) and next prime (20728387).

It is a cyclic number.

It is not a de Polignac number, because 20728339 - 2⁹ = 20727827 is a prime.

It is not a weakly prime, because it can be changed into another prime (20728139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10364169 + 10364170.

It is an arithmetic number, because the mean of its divisors is an integer number (10364170).

Almost surely, 2^20728339 is an apocalyptic number.

20728339 is a deficient number, since it is larger than the sum of its proper divisors (1).

20728339 is an equidigital number, since it uses as much as digits as its factorization.

20728339 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 20728339 is about 4552.8385651152. The cubic root of 20728339 is about 274.6975804966.

The spelling of 20728339 in words is "twenty million, seven hundred twenty-eight thousand, three hundred thirty-nine".