649866 has 16 divisors (see below), whose sum is σ = 1485504. Its totient is φ = 185664.

The previous prime is 649849. The next prime is 649867. The reversal of 649866 is 668946.

649866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (649867) by changing a digit.

649866 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7695 + ... + 7778.

It is an arithmetic number, because the mean of its divisors is an integer number (92844).

2⁶⁴⁹⁸⁶⁶ is an apocalyptic number.

649866 is an abundant number, since it is smaller than the sum of its proper divisors (835638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649866 is a wasteful number, since it uses less digits than its factorization.

649866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15485.

The product of its digits is 62208, while the sum is 39.

The square root of 649866 is about 806.1426672742. The cubic root of 649866 is about 86.6179575075.

The spelling of 649866 in words is "six hundred forty-nine thousand, eight hundred sixty-six".