649761 has 8 divisors (see below), whose sum is σ = 990144. Its totient is φ = 371280.

The previous prime is 649751. The next prime is 649769. The reversal of 649761 is 167946.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 649761 - 2⁶ = 649697 is a prime.

It is a congruent number.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15450 + ... + 15491.

It is an arithmetic number, because the mean of its divisors is an integer number (123768).

2⁶⁴⁹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

649761 is a deficient number, since it is larger than the sum of its proper divisors (340383).

649761 is a wasteful number, since it uses less digits than its factorization.

649761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30951.

The product of its digits is 9072, while the sum is 33.

The square root of 649761 is about 806.0775396945. The cubic root of 649761 is about 86.6132922507.

The spelling of 649761 in words is "six hundred forty-nine thousand, seven hundred sixty-one".