6447754440 has 256 divisors, whose sum is σ = 22422528000. Its totient is φ = 1646023680.

The previous prime is 6447754429. The next prime is 6447754459. The reversal of 6447754440 is 444577446.

It is a happy number.

6447754440 is a `hidden beast` number, since 64 + 4 + 7 + 7 + 544 + 40 = 666.

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

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, 3976830 + ... + 3978450.

It is an arithmetic number, because the mean of its divisors is an integer number (87588000).

Almost surely, 2^6447754440 is an apocalyptic number.

6447754440 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 6447754440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11211264000).

6447754440 is an abundant number, since it is smaller than the sum of its proper divisors (15974773560).

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

6447754440 is a wasteful number, since it uses less digits than its factorization.

6447754440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1797 (or 1787 counting only the distinct ones).

The product of its (nonzero) digits is 1505280, while the sum is 45.

The square root of 6447754440 is about 80297.9105581210. The cubic root of 6447754440 is about 1861.2419385121.

The spelling of 6447754440 in words is "six billion, four hundred forty-seven million, seven hundred fifty-four thousand, four hundred forty".