647949 has 4 divisors (see below), whose sum is σ = 863936. Its totient is φ = 431964.

The previous prime is 647917. The next prime is 647951. The reversal of 647949 is 949746.

647949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 647949 - 2⁵ = 647917 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 647949.

It is not an unprimeable number, because it can be changed into a prime (647909) 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, 107989 + ... + 107994.

It is an arithmetic number, because the mean of its divisors is an integer number (215984).

2⁶⁴⁷⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

647949 is a deficient number, since it is larger than the sum of its proper divisors (215987).

647949 is a wasteful number, since it uses less digits than its factorization.

647949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215986.

The product of its digits is 54432, while the sum is 39.

The square root of 647949 is about 804.9527936469. The cubic root of 647949 is about 86.5327039512.

It can be divided in two parts, 647 and 949, that added together give a triangular number (1596 = T₅₆).

The spelling of 647949 in words is "six hundred forty-seven thousand, nine hundred forty-nine".