647635 has 4 divisors (see below), whose sum is σ = 777168. Its totient is φ = 518104.

The previous prime is 647627. The next prime is 647641. The reversal of 647635 is 536746.

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

It is a cyclic number.

It is not a de Polignac number, because 647635 - 2³ = 647627 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 647597 and 647606.

It is an unprimeable number.

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, 64759 + ... + 64768.

It is an arithmetic number, because the mean of its divisors is an integer number (194292).

2⁶⁴⁷⁶³⁵ is an apocalyptic number.

647635 is a deficient number, since it is larger than the sum of its proper divisors (129533).

647635 is a wasteful number, since it uses less digits than its factorization.

647635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129532.

The product of its digits is 15120, while the sum is 31.

The square root of 647635 is about 804.7577275180. The cubic root of 647635 is about 86.5187236023.

Subtracting from 647635 its reverse (536746), we obtain a square (110889 = 333²).

The spelling of 647635 in words is "six hundred forty-seven thousand, six hundred thirty-five".