649664 has 14 divisors (see below), whose sum is σ = 1289304. Its totient is φ = 324800.

The previous prime is 649661. The next prime is 649697. The reversal of 649664 is 466946.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5012 + ... + 5139.

2⁶⁴⁹⁶⁶⁴ is an apocalyptic number.

649664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

649664 is a deficient number, since it is larger than the sum of its proper divisors (639640).

649664 is a wasteful number, since it uses less digits than its factorization.

649664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10163 (or 10153 counting only the distinct ones).

The product of its digits is 31104, while the sum is 35.

The square root of 649664 is about 806.0173695399. The cubic root of 649664 is about 86.6089819954.

The spelling of 649664 in words is "six hundred forty-nine thousand, six hundred sixty-four".