649918 has 8 divisors (see below), whose sum is σ = 984312. Its totient is φ = 321816.

The previous prime is 649907. The next prime is 649921. The reversal of 649918 is 819946.

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

It is a super-3 number, since 3×649918³ = 823563234333745896, which contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

649918 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 1305 + ... + 1732.

It is an arithmetic number, because the mean of its divisors is an integer number (123039).

2⁶⁴⁹⁹¹⁸ is an apocalyptic number.

649918 is a deficient number, since it is larger than the sum of its proper divisors (334394).

649918 is a wasteful number, since it uses less digits than its factorization.

649918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3146.

The product of its digits is 15552, while the sum is 37.

The square root of 649918 is about 806.1749189847. The cubic root of 649918 is about 86.6202677344.

The spelling of 649918 in words is "six hundred forty-nine thousand, nine hundred eighteen".