648685 has 4 divisors (see below), whose sum is σ = 778428. Its totient is φ = 518944.

The previous prime is 648677. The next prime is 648689. The reversal of 648685 is 586846.

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

It can be written as a sum of positive squares in 2 ways, for example, as 320356 + 328329 = 566^2 + 573^2 .

It is a cyclic number.

It is not a de Polignac number, because 648685 - 2³ = 648677 is a prime.

It is a Duffinian number.

648685 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648689) 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, 64864 + ... + 64873.

It is an arithmetic number, because the mean of its divisors is an integer number (194607).

2⁶⁴⁸⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

648685 is a deficient number, since it is larger than the sum of its proper divisors (129743).

648685 is a wasteful number, since it uses less digits than its factorization.

648685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129742.

The product of its digits is 46080, while the sum is 37.

The square root of 648685 is about 805.4098335630. The cubic root of 648685 is about 86.5654554852.

The spelling of 648685 in words is "six hundred forty-eight thousand, six hundred eighty-five".