648281808 has 120 divisors (see below), whose sum is σ = 1936034568. Its totient is φ = 201793536.

The previous prime is 648281783. The next prime is 648281813. The reversal of 648281808 is 808182846.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 254338704 + 393943104 = 15948^2 + 19848^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 334410 + ... + 336342.

Almost surely, 2^648281808 is an apocalyptic number.

648281808 is a gapful number since it is divisible by the number (68) 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 648281808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (968017284).

648281808 is an abundant number, since it is smaller than the sum of its proper divisors (1287752760).

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

648281808 is a wasteful number, since it uses less digits than its factorization.

648281808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2101 (or 2092 counting only the distinct ones).

The product of its (nonzero) digits is 196608, while the sum is 45.

The square root of 648281808 is about 25461.3787529270. The cubic root of 648281808 is about 865.4751676668.

The spelling of 648281808 in words is "six hundred forty-eight million, two hundred eighty-one thousand, eight hundred eight".