20728579 has 2 divisors, whose sum is σ = 20728580. Its totient is φ = 20728578.

The previous prime is 20728577. The next prime is 20728583. The reversal of 20728579 is 97582702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20728579 - 2¹ = 20728577 is a prime.

Together with 20728577, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20728571) 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, 10364289 + 10364290.

It is an arithmetic number, because the mean of its divisors is an integer number (10364290).

Almost surely, 2^20728579 is an apocalyptic number.

20728579 is a deficient number, since it is larger than the sum of its proper divisors (1).

20728579 is an equidigital number, since it uses as much as digits as its factorization.

20728579 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 20728579 is about 4552.8649222221. The cubic root of 20728579 is about 274.6986406743.

The spelling of 20728579 in words is "twenty million, seven hundred twenty-eight thousand, five hundred seventy-nine".