81840507840000 has 6000 divisors, whose sum is σ = 402515590755168. Its totient is φ = 16148201472000.

The previous prime is 81840507839971. The next prime is 81840507840001. The reversal of 81840507840000 is 4870504818.

It is a tau number, because it is divible by the number of its divisors (6000).

It is a super-3 number, since 3×81840507840000³ (a number of 43 digits) contains 333 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81840507840001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 599 ways as a sum of consecutive naturals, for example, 521277119922 + ... + 521277120078.

Almost surely, 2^{81840507840000} is an apocalyptic number.

81840507840000 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 81840507840000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (201257795377584).

81840507840000 is an abundant number, since it is smaller than the sum of its proper divisors (320675082915168).

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

81840507840000 is a wasteful number, since it uses less digits than its factorization.

81840507840000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 286720, while the sum is 45.

The spelling of 81840507840000 in words is "eighty-one trillion, eight hundred forty billion, five hundred seven million, eight hundred forty thousand".