647823 has 16 divisors (see below), whose sum is σ = 959616. Its totient is φ = 385440.

The previous prime is 647821. The next prime is 647837. The reversal of 647823 is 328746.

It is not a de Polignac number, because 647823 - 2¹ = 647821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647821) 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 15 ways as a sum of consecutive naturals, for example, 2065 + ... + 2357.

It is an arithmetic number, because the mean of its divisors is an integer number (59976).

2⁶⁴⁷⁸²³ is an apocalyptic number.

647823 is a deficient number, since it is larger than the sum of its proper divisors (311793).

647823 is a wasteful number, since it uses less digits than its factorization.

647823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374.

The product of its digits is 8064, while the sum is 30.

The square root of 647823 is about 804.8745243825. The cubic root of 647823 is about 86.5270945450.

It can be divided in two parts, 64 and 7823, that added together give a palindrome (7887).

The spelling of 647823 in words is "six hundred forty-seven thousand, eight hundred twenty-three".