20085905171 has 2 divisors, whose sum is σ = 20085905172. Its totient is φ = 20085905170.

The previous prime is 20085905167. The next prime is 20085905201. The reversal of 20085905171 is 17150958002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20085905171 - 2² = 20085905167 is a prime.

It is not a weakly prime, because it can be changed into another prime (20085905111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10042952585 + 10042952586.

It is an arithmetic number, because the mean of its divisors is an integer number (10042952586).

Almost surely, 2^20085905171 is an apocalyptic number.

20085905171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20085905171 is an equidigital number, since it uses as much as digits as its factorization.

20085905171 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 38.

The spelling of 20085905171 in words is "twenty billion, eighty-five million, nine hundred five thousand, one hundred seventy-one".