81381888000 has 1248 divisors, whose sum is σ = 356147301120. Its totient is φ = 17960140800.

The previous prime is 81381887963. The next prime is 81381888017. The reversal of 81381888000 is 88818318.

It is a happy number.

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 95 ways as a sum of consecutive naturals, for example, 2806271986 + ... + 2806272014.

It is an arithmetic number, because the mean of its divisors is an integer number (285374440).

Almost surely, 2^81381888000 is an apocalyptic number.

81381888000 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 81381888000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178073650560).

81381888000 is an abundant number, since it is smaller than the sum of its proper divisors (274765413120).

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

81381888000 is an equidigital number, since it uses as much as digits as its factorization.

81381888000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 98304, while the sum is 45.

The spelling of 81381888000 in words is "eighty-one billion, three hundred eighty-one million, eight hundred eighty-eight thousand".