647704 has 8 divisors (see below), whose sum is σ = 1214460. Its totient is φ = 323848.

The previous prime is 647693. The next prime is 647719. The reversal of 647704 is 407746.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40474 + ... + 40489.

2⁶⁴⁷⁷⁰⁴ is an apocalyptic number.

It is an amenable number.

647704 is a deficient number, since it is larger than the sum of its proper divisors (566756).

647704 is a wasteful number, since it uses less digits than its factorization.

647704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80969 (or 80965 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 28.

The square root of 647704 is about 804.8005964213. The cubic root of 647704 is about 86.5217961045.

The spelling of 647704 in words is "six hundred forty-seven thousand, seven hundred four".