6440480640 has 512 divisors, whose sum is σ = 25709875200. Its totient is φ = 1509580800.

The previous prime is 6440480611. The next prime is 6440480647. The reversal of 6440480640 is 460840446.

6440480640 is a `hidden beast` number, since 6 + 4 + 4 + 0 + 4 + 8 + 0 + 640 = 666.

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 = 6440480595 and 6440480604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440480647) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5891934 + ... + 5893026.

It is an arithmetic number, because the mean of its divisors is an integer number (50214600).

Almost surely, 2^6440480640 is an apocalyptic number.

6440480640 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 6440480640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12854937600).

6440480640 is an abundant number, since it is smaller than the sum of its proper divisors (19269394560).

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

6440480640 is a wasteful number, since it uses less digits than its factorization.

6440480640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163 (or 1145 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 36.

The square root of 6440480640 is about 80252.6051913581. The cubic root of 6440480640 is about 1860.5417776605.

The spelling of 6440480640 in words is "six billion, four hundred forty million, four hundred eighty thousand, six hundred forty".