81045861811200 has 5280 divisors, whose sum is σ = 370577955242880. Its totient is φ = 17237488435200.

The previous prime is 81045861811177. The next prime is 81045861811217. The reversal of 81045861811200 is 211816854018.

81045861811200 is a `hidden beast` number, since 8 + 1 + 0 + 4 + 5 + 8 + 618 + 1 + 1 + 20 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (5280).

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 479 ways as a sum of consecutive naturals, for example, 910627660756 + ... + 910627660844.

It is an arithmetic number, because the mean of its divisors is an integer number (70185218796).

Almost surely, 2^{81045861811200} is an apocalyptic number.

81045861811200 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 81045861811200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185288977621440).

81045861811200 is an abundant number, since it is smaller than the sum of its proper divisors (289532093431680).

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

81045861811200 is a wasteful number, since it uses less digits than its factorization.

81045861811200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 45.

The spelling of 81045861811200 in words is "eighty-one trillion, forty-five billion, eight hundred sixty-one million, eight hundred eleven thousand, two hundred".