6481531405440 has 5120 divisors, whose sum is σ = 32103070433280. Its totient is φ = 1208726323200.

The previous prime is 6481531405387. The next prime is 6481531405577. The reversal of 6481531405440 is 445041351846.

6481531405440 is a `hidden beast` number, since 6 + 48 + 1 + 53 + 14 + 0 + 544 + 0 = 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 639 ways as a sum of consecutive naturals, for example, 137904923497 + ... + 137904923543.

It is an arithmetic number, because the mean of its divisors is an integer number (6270130944).

Almost surely, 2^{6481531405440} is an apocalyptic number.

6481531405440 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 6481531405440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16051535216640).

6481531405440 is an abundant number, since it is smaller than the sum of its proper divisors (25621539027840).

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

6481531405440 is a wasteful number, since it uses less digits than its factorization.

6481531405440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 45.

The spelling of 6481531405440 in words is "six trillion, four hundred eighty-one billion, five hundred thirty-one million, four hundred five thousand, four hundred forty".