649841664 has 88 divisors (see below), whose sum is σ = 1742406400. Its totient is φ = 215322624.

The previous prime is 649841651. The next prime is 649841669. The reversal of 649841664 is 466148946.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (649841669) 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 7 ways as a sum of consecutive naturals, for example, 610797 + ... + 611859.

Almost surely, 2^649841664 is an apocalyptic number.

649841664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649841664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (871203200).

649841664 is an abundant number, since it is smaller than the sum of its proper divisors (1092564736).

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

649841664 is a wasteful number, since it uses less digits than its factorization.

649841664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1285 (or 1267 counting only the distinct ones).

The product of its digits is 995328, while the sum is 48.

The square root of 649841664 is about 25491.9921544002. The cubic root of 649841664 is about 866.1687627905.

The spelling of 649841664 in words is "six hundred forty-nine million, eight hundred forty-one thousand, six hundred sixty-four".