649944 has 80 divisors (see below), whose sum is σ = 1960200. Its totient is φ = 200448.

The previous prime is 649937. The next prime is 649969. The reversal of 649944 is 449946.

649944 is a `hidden beast` number, since 649 + 9 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (31104) is a multiple of the sum of its prime divisors (81).

It is a junction number, because it is equal to n+sod(n) for n = 649899 and 649908.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 649944.

It is an unprimeable number.

649944 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 (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10987 + ... + 11045.

2⁶⁴⁹⁹⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (980100).

649944 is an abundant number, since it is smaller than the sum of its proper divisors (1310256).

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

649944 is a wasteful number, since it uses less digits than its factorization.

649944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 81 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 649944 is about 806.1910443561. The cubic root of 649944 is about 86.6214228016.

The spelling of 649944 in words is "six hundred forty-nine thousand, nine hundred forty-four".