649764 has 18 divisors (see below), whose sum is σ = 1642550. Its totient is φ = 216576.

The previous prime is 649751. The next prime is 649769. The reversal of 649764 is 467946.

649764 is a `hidden beast` number, since 649 + 7 + 6 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 627264 + 22500 = 792^2 + 150^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18049 = 649764 / (6 + 4 + 9 + 7 + 6 + 4).

It is a plaindrome in base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 649764.

It is not an unprimeable number, because it can be changed into a prime (649769) by changing a digit.

649764 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 5 ways as a sum of consecutive naturals, for example, 8989 + ... + 9060.

2⁶⁴⁹⁷⁶⁴ is an apocalyptic number.

It is an amenable number.

649764 is an abundant number, since it is smaller than the sum of its proper divisors (992786).

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

649764 is a wasteful number, since it uses less digits than its factorization.

649764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18059 (or 18054 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 649764 is about 806.0794005556. The cubic root of 649764 is about 86.6134255507.

It can be divided in two parts, 64976 and 4, that added together give a triangular number (64980 = T₃₆₀).

The spelling of 649764 in words is "six hundred forty-nine thousand, seven hundred sixty-four".