647968 has 12 divisors (see below), whose sum is σ = 1275750. Its totient is φ = 323968.

The previous prime is 647963. The next prime is 647987. The reversal of 647968 is 869746.

It can be written as a sum of positive squares in only one way, i.e., 595984 + 51984 = 772^2 + 228^2 .

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 647968.

It is not an unprimeable number, because it can be changed into a prime (647963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10093 + ... + 10156.

2⁶⁴⁷⁹⁶⁸ is an apocalyptic number.

It is an amenable number.

647968 is a deficient number, since it is larger than the sum of its proper divisors (627782).

647968 is a wasteful number, since it uses less digits than its factorization.

647968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20259 (or 20251 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 647968 is about 804.9645954947. The cubic root of 647968 is about 86.5335497510.

It can be divided in two parts, 6 and 47968, that added together give a palindrome (47974).

The spelling of 647968 in words is "six hundred forty-seven thousand, nine hundred sixty-eight".