646478 has 16 divisors (see below), whose sum is σ = 1127904. Its totient is φ = 272160.

The previous prime is 646453. The next prime is 646519. The reversal of 646478 is 874646.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon 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 646478.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 476 + ... + 1232.

It is an arithmetic number, because the mean of its divisors is an integer number (70494).

2⁶⁴⁶⁴⁷⁸ is an apocalyptic number.

646478 is a deficient number, since it is larger than the sum of its proper divisors (481426).

646478 is a wasteful number, since it uses less digits than its factorization.

646478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827.

The product of its digits is 32256, while the sum is 35.

The square root of 646478 is about 804.0385562894. The cubic root of 646478 is about 86.4671709874.

The spelling of 646478 in words is "six hundred forty-six thousand, four hundred seventy-eight".