647859 has 4 divisors (see below), whose sum is σ = 863816. Its totient is φ = 431904.

The previous prime is 647851. The next prime is 647861. The reversal of 647859 is 958746.

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

It is not a de Polignac number, because 647859 - 2³ = 647851 is a prime.

It is a D-number.

It is a Duffinian number.

647859 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647859.

It is not an unprimeable number, because it can be changed into a prime (647851) 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, 107974 + ... + 107979.

It is an arithmetic number, because the mean of its divisors is an integer number (215954).

2⁶⁴⁷⁸⁵⁹ is an apocalyptic number.

647859 is a deficient number, since it is larger than the sum of its proper divisors (215957).

647859 is a wasteful number, since it uses less digits than its factorization.

647859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215956.

The product of its digits is 60480, while the sum is 39.

The square root of 647859 is about 804.8968878061. The cubic root of 647859 is about 86.5286973067.

The spelling of 647859 in words is "six hundred forty-seven thousand, eight hundred fifty-nine".