647291 has 4 divisors (see below), whose sum is σ = 656232. Its totient is φ = 638352.

The previous prime is 647263. The next prime is 647293. The reversal of 647291 is 192746.

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 647291 - 2¹⁰ = 646267 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647291.

It is not an unprimeable number, because it can be changed into a prime (647293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4361 + ... + 4506.

It is an arithmetic number, because the mean of its divisors is an integer number (164058).

2⁶⁴⁷²⁹¹ is an apocalyptic number.

647291 is a deficient number, since it is larger than the sum of its proper divisors (8941).

647291 is an equidigital number, since it uses as much as digits as its factorization.

647291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8940.

The product of its digits is 3024, while the sum is 29.

The square root of 647291 is about 804.5439702092. The cubic root of 647291 is about 86.5034023632.

The spelling of 647291 in words is "six hundred forty-seven thousand, two hundred ninety-one".