20728159 has 2 divisors, whose sum is σ = 20728160. Its totient is φ = 20728158.

The previous prime is 20728153. The next prime is 20728199. The reversal of 20728159 is 95182702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20728159 - 2⁹ = 20727647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20728153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10364079 + 10364080.

It is an arithmetic number, because the mean of its divisors is an integer number (10364080).

Almost surely, 2^20728159 is an apocalyptic number.

20728159 is a deficient number, since it is larger than the sum of its proper divisors (1).

20728159 is an equidigital number, since it uses as much as digits as its factorization.

20728159 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 20728159 is about 4552.8187971849. The cubic root of 20728159 is about 274.6967853580.

The spelling of 20728159 in words is "twenty million, seven hundred twenty-eight thousand, one hundred fifty-nine".