649865 has 8 divisors (see below), whose sum is σ = 813888. Its totient is φ = 497200.

The previous prime is 649849. The next prime is 649867. The reversal of 649865 is 568946.

649865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 649865 - 2⁴ = 649849 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 649865.

It is not an unprimeable number, because it can be changed into a prime (649867) 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, 2711 + ... + 2940.

It is an arithmetic number, because the mean of its divisors is an integer number (101736).

2⁶⁴⁹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

649865 is a deficient number, since it is larger than the sum of its proper divisors (164023).

649865 is a wasteful number, since it uses less digits than its factorization.

649865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5679.

The product of its digits is 51840, while the sum is 38.

The square root of 649865 is about 806.1420470364. The cubic root of 649865 is about 86.6179130789.

The spelling of 649865 in words is "six hundred forty-nine thousand, eight hundred sixty-five".