647911 has 4 divisors (see below), whose sum is σ = 706824. Its totient is φ = 589000.

The previous prime is 647909. The next prime is 647917. The reversal of 647911 is 119746.

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 647911 - 2¹ = 647909 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 647911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647917) 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, 29440 + ... + 29461.

It is an arithmetic number, because the mean of its divisors is an integer number (176706).

2⁶⁴⁷⁹¹¹ is an apocalyptic number.

647911 is a deficient number, since it is larger than the sum of its proper divisors (58913).

647911 is a wasteful number, since it uses less digits than its factorization.

647911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58912.

The product of its digits is 1512, while the sum is 28.

The square root of 647911 is about 804.9291894322. The cubic root of 647911 is about 86.5310123021.

The spelling of 647911 in words is "six hundred forty-seven thousand, nine hundred eleven".