81540813594240 has 4608 divisors, whose sum is σ = 418411019819520. Its totient is φ = 14714929152000.

The previous prime is 81540813594181. The next prime is 81540813594421. The reversal of 81540813594240 is 4249531804518.

81540813594240 is a `hidden beast` number, since 8 + 1 + 5 + 4 + 0 + 8 + 1 + 3 + 594 + 2 + 40 = 666.

It is a super-2 number, since 2×81540813594240² (a number of 29 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 29111320840 + ... + 29111323640.

It is an arithmetic number, because the mean of its divisors is an integer number (90801002565).

Almost surely, 2^{81540813594240} is an apocalyptic number.

81540813594240 is a gapful number since it is divisible by the number (80) 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 81540813594240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (209205509909760).

81540813594240 is an abundant number, since it is smaller than the sum of its proper divisors (336870206225280).

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

81540813594240 is a wasteful number, since it uses less digits than its factorization.

81540813594240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2894 (or 2859 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 54.

The spelling of 81540813594240 in words is "eighty-one trillion, five hundred forty billion, eight hundred thirteen million, five hundred ninety-four thousand, two hundred forty".