20728759 has 2 divisors, whose sum is σ = 20728760. Its totient is φ = 20728758.

The previous prime is 20728733. The next prime is 20728781. The reversal of 20728759 is 95782702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20728759 - 2¹¹ = 20726711 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20728159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10364379 + 10364380.

It is an arithmetic number, because the mean of its divisors is an integer number (10364380).

Almost surely, 2^20728759 is an apocalyptic number.

20728759 is a deficient number, since it is larger than the sum of its proper divisors (1).

20728759 is an equidigital number, since it uses as much as digits as its factorization.

20728759 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 20728759 is about 4552.8846899521. The cubic root of 20728759 is about 274.6994358021.

The spelling of 20728759 in words is "twenty million, seven hundred twenty-eight thousand, seven hundred fifty-nine".