649856 has 16 divisors (see below), whose sum is σ = 1294890. Its totient is φ = 324864.

The previous prime is 649849. The next prime is 649867. The reversal of 649856 is 658946.

It can be written as a sum of positive squares in only one way, i.e., 379456 + 270400 = 616^2 + 520^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2411 + ... + 2666.

2⁶⁴⁹⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

649856 is a deficient number, since it is larger than the sum of its proper divisors (645034).

649856 is an equidigital number, since it uses as much as digits as its factorization.

649856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5091 (or 5079 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 649856 is about 806.1364648743. The cubic root of 649856 is about 86.6175132190.

The spelling of 649856 in words is "six hundred forty-nine thousand, eight hundred fifty-six".