649949 has 4 divisors (see below), whose sum is σ = 653760. Its totient is φ = 646140.

The previous prime is 649937. The next prime is 649969. The reversal of 649949 is 949946.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649949 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1637 + ... + 1994.

It is an arithmetic number, because the mean of its divisors is an integer number (163440).

2⁶⁴⁹⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

649949 is a deficient number, since it is larger than the sum of its proper divisors (3811).

649949 is a wasteful number, since it uses less digits than its factorization.

649949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3810.

The product of its digits is 69984, while the sum is 41.

The square root of 649949 is about 806.1941453521. The cubic root of 649949 is about 86.6216449264.

The spelling of 649949 in words is "six hundred forty-nine thousand, nine hundred forty-nine".