640414944 has 384 divisors, whose sum is σ = 2187924480. Its totient is φ = 180652032.

The previous prime is 640414937. The next prime is 640414987. The reversal of 640414944 is 449414046.

640414944 is a `hidden beast` number, since 640 + 4 + 1 + 4 + 9 + 4 + 4 = 666.

640414944 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 = 640414899 and 640414908.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9558399 + ... + 9558465.

It is an arithmetic number, because the mean of its divisors is an integer number (5697720).

Almost surely, 2^640414944 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 640414944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1093962240).

640414944 is an abundant number, since it is smaller than the sum of its proper divisors (1547509536).

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

640414944 is a wasteful number, since it uses less digits than its factorization.

640414944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159 (or 145 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 640414944 is about 25306.4210033738. The cubic root of 640414944 is about 861.9600794744.

The spelling of 640414944 in words is "six hundred forty million, four hundred fourteen thousand, nine hundred forty-four".