645171 has 8 divisors (see below), whose sum is σ = 868560. Its totient is φ = 425952.

The previous prime is 645149. The next prime is 645179. The reversal of 645171 is 171546.

645171 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645171 - 2¹⁴ = 628787 is a prime.

645171 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645171.

It is not an unprimeable number, because it can be changed into a prime (645179) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 660 + ... + 1313.

It is an arithmetic number, because the mean of its divisors is an integer number (108570).

2⁶⁴⁵¹⁷¹ is an apocalyptic number.

645171 is a deficient number, since it is larger than the sum of its proper divisors (223389).

645171 is a wasteful number, since it uses less digits than its factorization.

645171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2085.

The product of its digits is 840, while the sum is 24.

The square root of 645171 is about 803.2253731052. The cubic root of 645171 is about 86.4088607596.

The spelling of 645171 in words is "six hundred forty-five thousand, one hundred seventy-one".