646487 has 4 divisors (see below), whose sum is σ = 654360. Its totient is φ = 638616.

The previous prime is 646453. The next prime is 646519. The reversal of 646487 is 784646.

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 646487 - 2⁶ = 646423 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 15.

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 646487.

It is not an unprimeable number, because it can be changed into a prime (646687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3812 + ... + 3977.

It is an arithmetic number, because the mean of its divisors is an integer number (163590).

2⁶⁴⁶⁴⁸⁷ is an apocalyptic number.

646487 is a deficient number, since it is larger than the sum of its proper divisors (7873).

646487 is an equidigital number, since it uses as much as digits as its factorization.

646487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7872.

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

The square root of 646487 is about 804.0441530165. The cubic root of 646487 is about 86.4675722389.

The spelling of 646487 in words is "six hundred forty-six thousand, four hundred eighty-seven".