647671 has 4 divisors (see below), whose sum is σ = 653832. Its totient is φ = 641512.

The previous prime is 647663. The next prime is 647687. The reversal of 647671 is 176746.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 647671 - 2³ = 647663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2920 + ... + 3133.

It is an arithmetic number, because the mean of its divisors is an integer number (163458).

2⁶⁴⁷⁶⁷¹ is an apocalyptic number.

647671 is a deficient number, since it is larger than the sum of its proper divisors (6161).

647671 is a wasteful number, since it uses less digits than its factorization.

647671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6160.

The product of its digits is 7056, while the sum is 31.

The square root of 647671 is about 804.7800941872. The cubic root of 647671 is about 86.5203266742.

The spelling of 647671 in words is "six hundred forty-seven thousand, six hundred seventy-one".