645436171 has 2 divisors, whose sum is σ = 645436172. Its totient is φ = 645436170.

The previous prime is 645436159. The next prime is 645436193. The reversal of 645436171 is 171634546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645436171 - 2¹⁵ = 645403403 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645436171.

It is not a weakly prime, because it can be changed into another prime (645136171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322718085 + 322718086.

It is an arithmetic number, because the mean of its divisors is an integer number (322718086).

Almost surely, 2^645436171 is an apocalyptic number.

645436171 is a deficient number, since it is larger than the sum of its proper divisors (1).

645436171 is an equidigital number, since it uses as much as digits as its factorization.

645436171 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 37.

The square root of 645436171 is about 25405.4358553440. The cubic root of 645436171 is about 864.2069740737.

The spelling of 645436171 in words is "six hundred forty-five million, four hundred thirty-six thousand, one hundred seventy-one".