6440405760 has 216 divisors, whose sum is σ = 22342800480. Its totient is φ = 1712848896.

The previous prime is 6440405759. The next prime is 6440405761. The reversal of 6440405760 is 675040446.

6440405760 is a `hidden beast` number, since 6 + 4 + 40 + 40 + 576 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (6440405759) and next prime (6440405761).

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

It is not an unprimeable number, because it can be changed into a prime (6440405761) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8374656 + ... + 8375424.

Almost surely, 2^6440405760 is an apocalyptic number.

6440405760 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 6440405760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11171400240).

6440405760 is an abundant number, since it is smaller than the sum of its proper divisors (15902394720).

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

6440405760 is a wasteful number, since it uses less digits than its factorization.

6440405760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523 (or 1506 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The square root of 6440405760 is about 80252.1386630911. The cubic root of 6440405760 is about 1860.5345671268.

The spelling of 6440405760 in words is "six billion, four hundred forty million, four hundred five thousand, seven hundred sixty".