647305 has 4 divisors (see below), whose sum is σ = 776772. Its totient is φ = 517840.

The previous prime is 647303. The next prime is 647321. The reversal of 647305 is 503746.

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 147456 + 499849 = 384^2 + 707^2 .

It is not a de Polignac number, because 647305 - 2¹ = 647303 is a prime.

It is a Duffinian number.

647305 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 647305.

It is not an unprimeable number, because it can be changed into a prime (647303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64726 + ... + 64735.

It is an arithmetic number, because the mean of its divisors is an integer number (194193).

2⁶⁴⁷³⁰⁵ is an apocalyptic number.

It is an amenable number.

647305 is a deficient number, since it is larger than the sum of its proper divisors (129467).

647305 is a wasteful number, since it uses less digits than its factorization.

647305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129466.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 647305 is about 804.5526707432. The cubic root of 647305 is about 86.5040260079.

The spelling of 647305 in words is "six hundred forty-seven thousand, three hundred five".