649904 has 20 divisors (see below), whose sum is σ = 1272240. Its totient is φ = 321600.

The previous prime is 649897. The next prime is 649907. The reversal of 649904 is 409946.

It is a happy number.

649904 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (649907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2282 + ... + 2550.

It is an arithmetic number, because the mean of its divisors is an integer number (63612).

2⁶⁴⁹⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

649904 is a deficient number, since it is larger than the sum of its proper divisors (622336).

649904 is a wasteful number, since it uses less digits than its factorization.

649904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 649904 is about 806.1662359588. The cubic root of 649904 is about 86.6196457624.

The spelling of 649904 in words is "six hundred forty-nine thousand, nine hundred four".