20851728571 has 2 divisors, whose sum is σ = 20851728572. Its totient is φ = 20851728570.

The previous prime is 20851728551. The next prime is 20851728613. The reversal of 20851728571 is 17582715802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20851728571 - 2¹⁷ = 20851597499 is a prime.

It is not a weakly prime, because it can be changed into another prime (20851728551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10425864285 + 10425864286.

It is an arithmetic number, because the mean of its divisors is an integer number (10425864286).

Almost surely, 2^20851728571 is an apocalyptic number.

20851728571 is a deficient number, since it is larger than the sum of its proper divisors (1).

20851728571 is an equidigital number, since it uses as much as digits as its factorization.

20851728571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 313600, while the sum is 46.

The spelling of 20851728571 in words is "twenty billion, eight hundred fifty-one million, seven hundred twenty-eight thousand, five hundred seventy-one".