81378791424000 has 2048 divisors, whose sum is σ = 355102477516800. Its totient is φ = 17995530240000.

The previous prime is 81378791423939. The next prime is 81378791424011. The reversal of 81378791424000 is 42419787318.

81378791424000 is a `hidden beast` number, since 8 + 1 + 37 + 87 + 91 + 42 + 400 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2048).

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 127 ways as a sum of consecutive naturals, for example, 23998462305 + ... + 23998465695.

It is an arithmetic number, because the mean of its divisors is an integer number (173389881600).

Almost surely, 2^{81378791424000} is an apocalyptic number.

81378791424000 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 81378791424000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177551238758400).

81378791424000 is an abundant number, since it is smaller than the sum of its proper divisors (273723686092800).

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

81378791424000 is an equidigital number, since it uses as much as digits as its factorization.

81378791424000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3483 (or 3439 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 54.

The spelling of 81378791424000 in words is "eighty-one trillion, three hundred seventy-eight billion, seven hundred ninety-one million, four hundred twenty-four thousand".