648771840 has 216 divisors, whose sum is σ = 2263934400. Its totient is φ = 171528192.

The previous prime is 648771803. The next prime is 648771859. The reversal of 648771840 is 48177846.

It is a Cunningham number, because it is equal to 25471²-1.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable 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 23 ways as a sum of consecutive naturals, for example, 2292339 + ... + 2292621.

Almost surely, 2^648771840 is an apocalyptic number.

648771840 is a gapful number since it is divisible by the number (60) 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 648771840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1131967200).

648771840 is an abundant number, since it is smaller than the sum of its proper divisors (1615162560).

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

648771840 is a wasteful number, since it uses less digits than its factorization.

648771840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509 (or 492 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The square root of 648771840 is about 25470.9999803698. Note that the first 4 decimals coincide. The cubic root of 648771840 is about 865.6931817599.

The spelling of 648771840 in words is "six hundred forty-eight million, seven hundred seventy-one thousand, eight hundred forty".