647798 has 4 divisors (see below), whose sum is σ = 971700. Its totient is φ = 323898.

The previous prime is 647789. The next prime is 647809. The reversal of 647798 is 897746.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 897746 = 2 ⋅448873.

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 647798.

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 as a sum of consecutive naturals, namely, 161948 + ... + 161951.

It is an arithmetic number, because the mean of its divisors is an integer number (242925).

2⁶⁴⁷⁷⁹⁸ is an apocalyptic number.

647798 is a deficient number, since it is larger than the sum of its proper divisors (323902).

647798 is a wasteful number, since it uses less digits than its factorization.

647798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323901.

The product of its digits is 84672, while the sum is 41.

The square root of 647798 is about 804.8589938617. The cubic root of 647798 is about 86.5259814811.

The spelling of 647798 in words is "six hundred forty-seven thousand, seven hundred ninety-eight".