647005 has 4 divisors (see below), whose sum is σ = 776412. Its totient is φ = 517600.

The previous prime is 646993. The next prime is 647011. The reversal of 647005 is 500746.

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

It can be written as a sum of positive squares in 2 ways, for example, as 158404 + 488601 = 398^2 + 699^2 .

It is a de Polignac number, because none of the positive numbers 2^k-647005 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64696 + ... + 64705.

It is an arithmetic number, because the mean of its divisors is an integer number (194103).

2⁶⁴⁷⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

647005 is a deficient number, since it is larger than the sum of its proper divisors (129407).

647005 is a wasteful number, since it uses less digits than its factorization.

647005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129406.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 647005 is about 804.3662101307. The cubic root of 647005 is about 86.4906602232.

The spelling of 647005 in words is "six hundred forty-seven thousand, five".