646560144 has 100 divisors (see below), whose sum is σ = 1906843356. Its totient is φ = 211431168.

The previous prime is 646560127. The next prime is 646560181. The reversal of 646560144 is 441065646.

646560144 is a `hidden beast` number, since 6 + 4 + 6 + 5 + 601 + 44 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 590490000 + 56070144 = 24300^2 + 7488^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 646560099 and 646560108.

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 19 ways as a sum of consecutive naturals, for example, 63982 + ... + 73394.

Almost surely, 2^646560144 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 646560144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (953421678).

646560144 is an abundant number, since it is smaller than the sum of its proper divisors (1260283212).

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

646560144 is a wasteful number, since it uses less digits than its factorization.

646560144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9486 (or 9471 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 646560144 is about 25427.5469520754. The cubic root of 646560144 is about 864.7083311688.

The spelling of 646560144 in words is "six hundred forty-six million, five hundred sixty thousand, one hundred forty-four".