171840648779 has 2 divisors, whose sum is σ = 171840648780. Its totient is φ = 171840648778.

The previous prime is 171840648761. The next prime is 171840648797. The reversal of 171840648779 is 977846048171.

Together with next prime (171840648797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (171840648761) and next prime (171840648797).

It is a cyclic number.

It is not a de Polignac number, because 171840648779 - 2³⁶ = 103121172043 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (171840648479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85920324389 + 85920324390.

It is an arithmetic number, because the mean of its divisors is an integer number (85920324390).

Almost surely, 2^171840648779 is an apocalyptic number.

171840648779 is a deficient number, since it is larger than the sum of its proper divisors (1).

171840648779 is an equidigital number, since it uses as much as digits as its factorization.

171840648779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18966528, while the sum is 62.

The spelling of 171840648779 in words is "one hundred seventy-one billion, eight hundred forty million, six hundred forty-eight thousand, seven hundred seventy-nine".