6581120986440 has 4320 divisors, whose sum is σ = 32586604336440. Its totient is φ = 1179493539840.

The previous prime is 6581120986423. The next prime is 6581120986477. The reversal of 6581120986440 is 446890211856.

6581120986440 is a `hidden beast` number, since 6 + 5 + 8 + 112 + 0 + 9 + 86 + 440 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4328005908996 + 2253115077444 = 2080386^2 + 1501038^2 .

It is a super-2 number, since 2×6581120986440² (a number of 26 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 1079 ways as a sum of consecutive naturals, for example, 90152342244 + ... + 90152342316.

Almost surely, 2^{6581120986440} is an apocalyptic number.

6581120986440 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 6581120986440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16293302168220).

6581120986440 is an abundant number, since it is smaller than the sum of its proper divisors (26005483350000).

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

6581120986440 is a wasteful number, since it uses less digits than its factorization.

6581120986440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 3317760, while the sum is 54.

The spelling of 6581120986440 in words is "six trillion, five hundred eighty-one billion, one hundred twenty million, nine hundred eighty-six thousand, four hundred forty".